Answer:
41L
Explanation:
Of a 4.8x10⁻⁵M mercury (II) iodide that contains 900mg of mercury (II) iodide. 2 significant digits
Molarity, M, is an unit of concentration in chemistry defined as the ratio between moles of solute (Mercury (II) iodide in this case) per Liter of solution.
A 4.8x10⁻⁵M solution contains 4.8x10⁻⁵ moles of solute per liter.
Now, 900mg = 0.900g of mercury (II) iodide (Molar mass: 454.4g/mol) are:
0.900g × (1mol / 454.4g) = 1.98x10⁻³moles of HgI₂
If in 1L there are 4.8x10⁻⁵ moles of HgI₂, There are 1.98x10⁻³moles of HgI₂ in:
1.98x10⁻³moles of HgI₂ ₓ (1L / 4.8x10⁻⁵moles) =
41LFor each of the following, classify the substance as a strong acid, strong base, weak acid, or weak base (or perhaps not acidic or basic). Then determine the pH of the solution and calculate the concentrations of all aqueous species present in the solution.a. 2.0 × 10 ^–2 M HBrb. 1.0 × 10^–4 M NaOHc. 0.0015 M Ba(OH)2 d. 0.25 M HCN e. 2.0 × 10 ^–10 M KOH f. 0.050 M NH3 g. 0.100 M NH4Cl h. 0.200 M CaF2 i. 0.0500 M Ba(NO3)2 j. 0.100 M Al(NO3)3
Answer:
a. Strong acid, pH = 1.69
b. Strong base, pH = 10
c. Strong base, pH = 11
d. Weak acid, pH = 4.90
e. Strong base, pH ≅ 7 (pH should be higher than 7, but the base is so diluted)
f. Weak base, pH = 10.96
g. Acidic salt, pH = 5.12
h. Basic salt, pH = 8.38
i. Neutral salt, pH = 7
j. Acidic salt, pH < 7
Explanation:
a. HBr → H⁺ + Br⁻
Hydrobromic acid is a strong acid.
pH = - log [H⁺]
- log 0.02 = 1.69
b. NaOH → Na⁺ + OH⁻
Sodium hydroxide is a strong base.
pH = 14 - pOH
pOH = - log [OH⁻]
pH = 14 - (-log 0.0001) = 10
c. Ba(OH)₂ → Ba²⁺ + 2OH⁻
Barium hydroxide is a strong base
[OH⁻] = 2 . 0.0015 = 0.003M
pH = 14 - (-log 0.003) = 11
d. HCN + H₂O ⇄ H₃O⁺ + CN⁻
This is a weak acid, it reacts in water to make an equilibrium between the given protons and cyanide anion.
To calculate the [H₃O⁺] we must apply, the Ka
Ka = [H₃O⁺] . [CN⁻] / [HCN]
6.2×10⁻¹⁰ = x² / 0.25-x
As Ka is really small, we can not consider the x in the divisor, so we avoid the quadratic formula.
[H₃O⁺] = √(6.2×10⁻¹⁰ . 0.25) = 1.24×10⁻⁵
-log 1.24×10⁻⁵ = 4.90 → pH
e. KOH → K⁺ + OH⁻
2×10⁻¹⁰ M → It is a very diluted concentration, so we must consider the OH⁻ which are given, by water.
In this case, we propose the mass and charges balances equations.
Analytic concentration of base = 2×10⁻¹⁰ M = K⁺
[OH⁻] = K⁺ + H⁺ → Charges balance
The solution's hydroxides are given by water and the strong base.
Remember that Kw = H⁺ . OH⁻, so H⁺ = Kw/OH⁻
[OH⁻] = K⁺ + Kw/OH⁻. Let's solve the quadratic equation.
[OH⁻] = 2×10⁻¹⁰ + 1×10⁻¹⁴ /OH⁻
OH⁻² = 2×10⁻¹⁰. OH⁻ + 1×10⁻¹⁴
2×10⁻¹⁰. OH⁻ + 1×10⁻¹⁴ - OH⁻²
We finally arrived at the answer [OH⁻] = 1.001ₓ10⁻⁷
pH = 14 - (- log1.001ₓ10⁻⁷) = 7
The strong base is soo diluted, that water makes the pH be a neutral value.
Be careful, if you determine the [OH⁻] as - log 2×10⁻¹⁰, because you will obtain as pOH 9.69, so the pH would be 4.31. It is not possible, KOH is a strong base and 4.30 is an acid pH.
f. Ammonia is a weak base.
NH₃ + H₂O ⇄ NH₄⁺ + OH⁻
Kb = OH⁻ . NH₄⁺ / NH₃
1.74×10⁻⁵ = x² / 0.05 - x
We can avoid the x from the divisor, so:
[OH⁻] = √(1.74×10⁻⁵ . 0.05) = 9.32×10⁻⁴
pH = 14 - (-log 9.32×10⁻⁴ ) = 10.96
g. NH₄Cl, an acid salt. We dissociate the compound:
NH₄Cl → NH₄⁺ + Cl⁻. We analyse the ions:
Cl⁻ does not make hydrolisis to water. In the opposide, the ammonium can react given OH⁻ to medium, that's why the salt is acid, and pH sould be lower than 7
NH₄⁺ + H₂O ⇄ NH₃ + H₃O⁺ Ka
Ka = NH₃ . H₃O⁺ / NH₄⁺
5.70×10⁻¹⁰ = x² / 0.1 -x
[H₃O⁺] = √ (5.70×10⁻¹⁰ . 0.1) = 7.55×10⁻⁶
pH = - log 7.55×10⁻⁶ = 5.12
As Ka is so small, we avoid the x from the divisor.
h. CaF₂ → Ca²⁺ + 2F⁻
This is a basic salt.
The Ca²⁺ does not react to water. F⁻ can make hydrolisis because, the anion is the strong conjugate base, of a weak acid.
F⁻ + H₂O ⇄ HF + OH⁻ Kb
Kb = x² / 2 . 0.2 - x
Remember that, in the original salt we have an stoichiometry of 1:2, so 1 mol of calcium flouride may have 2 moles of flourides.
As Kb is small, we avoid the x, so:
[OH⁻] = √(1.47×10⁻¹¹ . 2 . 0.2) = 2.42×10⁻⁵
14 - (-log 2.42×10⁻⁵) = pH → 8.38
i . Neutral salt
BaNO₃₂ → Ba²⁺ + 2NO₃⁻
Ba²⁺ comes from a strong base, so it is the conjugate weak acid and it does not react to water. The same situation to the nitrate anion. (The conjugate weak base, from a strong acid, HNO₃)
pH = 7
j. Al(NO₃)₃, this is an acid salt.
Al(NO₃)₃ → Al³⁺ + 3NO₃⁻
The nitrate anion is the conjugate weak base, from a strong acid, HNO₃ so it does not make hydrolisis. The Al³⁺ comes from the Al(OH)₃ which is an amphoterous compound (it can react as an acid or a base) but the cation has an acidic power.
Al·(H₂O)₆³⁺ + H₂O ⇄ Al·(H₂O)₅(OH)²⁺ + H₃O⁺
Modern atomic theory states that atoms are neutral. How is this neutrality achieved in atoms? (2 points)
Ag+(aq)+2NH3(aq)⇌Ag(NH3)2+(aq) : A g + ( a q ) + 2 N H 3 ( a q ) ⇌ A g ( N H 3 ) 2 + ( a q ) : blank is the Lewis acid and blank is the Lewis base. is the Lewis acid and A g + ( a q ) + 2 N H 3 ( a q ) ⇌ A g ( N H 3 ) 2 + ( a q ) : blank is the Lewis acid and blank is the Lewis base. is the Lewis base.
Answer:
Silver ion - Lewis acid, Ammonia - Lewis base
Explanation:
The reaction is given as;
Ag+(aq) + 2NH3(aq) ⇌ [Ag(NH3)]2+(aq)
A lewis acid is an electron pair acceptor. While a lewis base is any substance that that can donate a pair of nonbonding electrons.
This reaction however is a complexation reaction, where ammonia is reacting with the silver ion.
Silver ion accepts electrons in this reaction, hence it is the lewis acid. The ammonia on the other hand donates the electrons used in bonding so it is the lewis base.
Medical implants and high-quality jewelry items for body piercings are frequently made of a material known as G23Ti or surgical-grade titanium. The percent composition of the material is 64.39% titanium, 24.19% aluminum, and 11.42% vanadium. What is the empirical formula for surgical-grade titanium
Answer:
The Empirical Formular is given as; Ti₆Al₄V
Explanation:
The percent composition of the material is 64.39% titanium, 24.19% aluminum, and 11.42% vanadium.
Elements Titanium Aluminium Vanadium
Percentage 64.39 24.19 11.42
Divide all through by their molar mass
64.39 / 47.87 24.19 / 27 11.42 / 50.94
= 1.345 = 0.896 = 0.224
Divide all though by the smallest number (0.224)
1.345 / 0.224 0.896 / 0.224 0.224 / 0.224
= 6 = 4 = 1
The Empirical Formular is given as; Ti₆Al₄V
Using the stepwise procedure for obtaining the empirical formula of a compound, the empirical formula is [tex] T_{6}Al_{4}V[/tex]
Titanium :
Percentage composition = 64.39%Molar mass = 47.87Divide by Molar mass : = 64.39/47.87 = 1.345
Aluminum :
Percentage composition = 24.19%Molar mass = 27Divide by Molar mass : = 24.19/27 = 0.896
Vanadium :
Percentage composition = 11.42%Molar mass = 50.94%Divide by Molar mass : = 11.42/50.94 = 0.224
Divide by the smallest :
Titanium = 1.345 / 0.224 = 6.00
Aluminum = 0.896 / 0.224 = 4
Vanadium = 0.224 / 0.224 = 1
Hence, the empirical formula is [tex] T_{6}Al_{4}V[/tex]
Learn more : https://brainly.com/question/17091379
A compound containing only C, H, and O, was extracted from the bark of the sassafras tree. The combustion of 32.3 mg produced 87.7 mg of CO2 and 18.0 mg of H2O. The molar mass of the compound was 162 g/mol. Determine its empirical and molecular formulas.
Answer:
Empirical formula: C₅H₅O
Molecular formula: C₁₀H₁₀O₂
Explanation:
When a compound containing C, H and O elements is combusted, the general reaction is:
CₐHₓOₙ + O₂ → a CO₂ + X/2 H₂O
Thus, you can find moles of carbon and hydrogen knowing moles of CO₂ and H₂O that are produced.
Moles CO₂ = Moles C = 0.0877g × (1mol / 44g) =
2.0x10⁻³ moles of CO₂ = moles C
Moles H₂O = 1/2 Moles H = 0.018g × (1mol / 18g) =
1x10⁻³ moles of H₂O; 2.0x10⁻³ moles H
The mass of the moles of C and H are:
2x10⁻³ moles C ₓ (12g / mol) = 0.024g C
2x10⁻³ moles H ₓ (1g / mol) = 0.002g H
Thus, mass of Oxygen is 32.3mg - 24mg C - 2mg O = 6.3mg O
Moles are:
0.0063g O ₓ (1mol / 16g) = 4x10⁻⁴ moles O
Empirical formula is the simplest ratio of atoms in a compound. Dividing each amount of moles for each atom in the 4x10⁻⁴ moles of oxygen (The lower moles), you will obtain:
C: 2.0x10⁻³ / 4x10⁻⁴ = 5
H: 2.0x10⁻³ / 4x10⁻⁴ = 5
O: 4x10⁻⁴ / 4x10⁻⁴ = 1
Thus, empirical formula is:
C₅H₅OThe molar mass of the empirical formula is:
12×5 + 1×5 + 16×1 = 81g/mol
As molar mass of the compound is 162g/mol, molecular formula is twice empirical formula:
C₁₀H₁₀O₂What was Ernest Rutherford experiment
A strontium hydroxide solution is prepared by dissolving 10.60 gg of Sr(OH)2Sr(OH)2 in water to make 47.00 mLmL of solution.What is the molarity of this solution? Express your answer to four significant figures and include the appropriate units.
Answer:
Approximately [tex]1.854\; \rm mol\cdot L^{-1}[/tex].
Explanation:
Note that both figures in the question come with four significant figures. Therefore, the answer should also be rounded to four significant figures. Intermediate results should have more significant figures than that.
Formula mass of strontium hydroxideLook up the relative atomic mass of [tex]\rm Sr[/tex], [tex]\rm O[/tex], and [tex]\rm H[/tex] on a modern periodic table. Keep at least four significant figures in each of these atomic mass data.
[tex]\rm Sr[/tex]: [tex]87.62[/tex].[tex]\rm O[/tex]: [tex]15.999[/tex].[tex]\rm H[/tex]: [tex]1.008[/tex].Calculate the formula mass of [tex]\rm Sr(OH)_2[/tex]:
[tex]M\left(\rm Sr(OH)_2\right) = 87.62 + 2\times (15.999 + 1.008) = 121.634\; \rm g \cdot mol^{-1}[/tex].
Number of moles of strontium hydroxide in the solution[tex]M\left(\rm Sr(OH)_2\right) =121.634\; \rm g \cdot mol^{-1}[/tex] means that each mole of [tex]\rm Sr(OH)_2[/tex] formula units have a mass of [tex]121.634\; \rm g[/tex].
The question states that there are [tex]10.60\; \rm g[/tex] of [tex]\rm Sr(OH)_2[/tex] in this solution.
How many moles of [tex]\rm Sr(OH)_2[/tex] formula units would that be?
[tex]\begin{aligned}n\left(\rm Sr(OH)_2\right) &= \frac{m\left(\rm Sr(OH)_2\right)}{M\left(\rm Sr(OH)_2\right)}\\ &= \frac{10.60\; \rm g}{121.634\; \rm g \cdot mol^{-1}} \approx 8.71467\times 10^{-2}\; \rm mol\end{aligned}[/tex].
Molarity of this strontium hydroxide solutionThere are [tex]8.71467\times 10^{-2}\; \rm mol[/tex] of [tex]\rm Sr(OH)_2[/tex] formula units in this [tex]47\; \rm mL[/tex] solution. Convert the unit of volume to liter:
[tex]V = 47\; \rm mL = 0.047\; \rm L[/tex].
The molarity of a solution measures its molar concentration. For this solution:
[tex]\begin{aligned}c\left(\rm Sr(OH)_2\right) &= \frac{n\left(\rm Sr(OH)_2\right)}{V}\\ &= \frac{8.71467\times 10^{-2}\; \rm mol}{0.047\; \rm L} \approx 1.854\; \rm mol \cdot L^{-1}\end{aligned}[/tex].
(Rounded to four significant figures.)
Rank the compounds in each set in order of increasing acid strength.
(a) CH3CH2COOH CH3CHBrCOOH CH3CBr2COOH
(b) CH3CH2CH2CHBrCOOH CH3CH2CHBrCH2COOH CH3CHBrCH2CH2COOH
Answer:
See explanation
Explanation:
For this question, we have to remember the effect of an atom with high electronegativity as "Br". If the "Br" atom is closer to the carboxylic acid group (COOH) we will have an inductive effect. Due to the electronegativity of Br, the electrons of the C-H bond would be to the Br, then this bond would be weaker and the compound will be more acid (because is easier to produce the hydronium ion [tex]H^+[/tex]).
With this in mind, for A in the last compound, we have 2 Br atoms near to the acid carboxylic group, so, we will have a high inductive effect, then the C-H would be weaker and we will have more acidity. Then we will have the compound with only 1 Br atom and finally, the last compound would be the one without Br atoms.
In B, the difference between the molecules is the position of the "Br" atom in the molecule. If the Br atom is closer to the acid group we will have a higher inductive effect and more acidity.
See figure 1
I hope it helps!
Use your periodic table and calculator as needed for the following question.
How much stock solution is needed to make 250 mL of a 6.0M solution. The molarity of the stock solution is 18M.
Selections may be rounded so choose the best answer.
56 mL
83 mL
2.3 mL
4.7 ml
A reaction mixture at 175 K initially contains 522 torr of NO and 421 torr of O2. At equilibrium, the total pressure in the reaction mixture is 748 torr. Calculate Kp at this temperature. Express your answer to three significant figures.
Answer:
[tex]Kp=0.0386[/tex]
Explanation:
Hello,
In this case, the undergoing chemical reaction is:
[tex]2NO+O_2\rightleftharpoons 2NO_2[/tex]
For which the equilibrium expression is:
[tex]Kp=\frac{p_{NO_2}^2}{p_{NO}^2p_{O_2}}[/tex]
Whereas, at equilibrium, each pressure is computed in terms of the initial pressure and the reaction extent via:
[tex]p_{NO_2}=2x\\p_{NO}=522-2x\\p_{O_2}=421-x[/tex]
And the total pressure:
[tex]p_{eq}=p_{NO_2}+p_{NO}+p_{O_2}\\\\p_{eq}=2x+522-2x+421-x\\\\p_{eq}=943-x[/tex]
Yet it is 748 torr, for which the extent is:
[tex]x=943-p_{eq}=943-748\\\\x=195torr[/tex]
Therefore, Kp turns out:
[tex]Kp=\frac{(2x)^2}{(522-2x)^2(421-x)}\\\\Kp=\frac{(2*195)^2}{(522-2*195)^2(421-195)}\\\\Kp=0.0386[/tex]
Best regards.
A diode has IS = 10−17 A and n = 1.05. (a) What is the diode voltage if the diode current is 70 μA? (b) What is the diode current for VD = 0.1 mV?
Answer:
(a) The diode voltage, [tex]V_D =[/tex] 0.776 V
(b) The diode current, [tex]I_D =[/tex] 3.81 x 10⁻²⁰ A
Explanation:
Given;
saturation current in diode, [tex]I_s[/tex] = 10⁻¹⁷ A
nonideality factor, n = 1.05
(a) the diode voltage
Given diode current, [tex]I_D[/tex] = 70 μA = 7 x 10⁻⁶ A
Diode voltage is calculated as;
[tex]V_D = nV_Tln(1+ \frac{I_D}{I_S} )[/tex]
Where;
[tex]V_T[/tex] is thermal voltage at 25°C = 0.025
[tex]V_D = 1.05 * 0.025 ln(1+ \frac{70*10^{-6}}{1*10^{-17}})\\\\V_D = 0.02625ln(1+ 7*10^{12})\\\\V_D = 0.776 \ V[/tex]
b) the diode current for VD = 0.1 mV
[tex]V_D = nV_Tln(1 +\frac{I_D}{I_S} )\\\\ln(1 +\frac{I_D}{I_S} ) = \frac{V_D}{nV_T} \\\\ln(1 +\frac{I_D}{I_S} ) = \frac{0.1*10^{-3}}{1.05*0.025} \\\\ln(1 +\frac{I_D}{I_S} ) = 0.00381\\\\1 +\frac{I_D}{I_S} = e^{0.00381}\\\\1+ \frac{I_D}{I_S}= 1.00381\\\\ \frac{I_D}{I_S}=1.00381 - 1\\\\ \frac{I_D}{I_S}= 0.00381\\\\I_D = 0.00381(I_S)\\\\I_D = 0.00381(10^{-17})\\\\I_D = 3.81*10^{-20} \ A[/tex]
When a 2.75g sample of liquid octane (C8H18) is burned in a bomb calorimeter, the temperature of the calorimeter rises from 22.0 °C to 41.5 °C. The heat capacity of the calorimeter, measured in a separate experiment, is 6.18 kJ/°C. Determine the ΔE for octane combustion in units of kJ/mol octane.
Answer:
THE HEAT OF COMBUSTION IS 4995.69 kJ/mol OF OCTANE.
Explanation:
Heat capacity = 6.18 kJ/C
Temperature change = 41.5 C - 22.0 C = 19.5 C
Heat required to raise the temperature by 19.5 °C is:
Heat = heat capacity * temperature change
Heat = 6.18 kJ/ C * 19.5 C
heat = 120.51 kJ of heat
120.51 kJ of heat is required to raise the temperature of 2.75 g sample of a liquid octane.
Molar mass of octane = ( 12* 8 + 1 * 18) = 114 g/mol
So therefore, the heat of the reaction per mole of octane will be:
120.51 kJ of heat is required for 2.75 g of octane
x J of heat will be required for 114 g of octane
x J = 120.51kJ * 114 / 2.75
x = 4995.69 kJ of heat per mole.
In conclusion, the heat of the combustion reaction in kJ / mole of octane is 4995.69 kJ/mol
Q1) How much heat is released when 6.38 grams of Ag(s) (m.m = 107.9 g/mol) reacts by the equation shown below at
standard state conditions?
4A9 (s) + 2H,Sq) + O2(g)
2Ag $(s) + 2H200)
Substance
AHof (kJ/mol)
-20.6
H259)
Ag2S (5)
H200
-32.6
-285.8
a)
8.80 KI
b) 69.9 kJ
C) 22.1 kJ
d) 90.8 kJ
e) 40.5 kJ
Answer:
The correct answer is -8.80 kJ.
Explanation:
The ΔH° can be determined by using the formula,
ΔH°rxn = ΔH°f (products) - ΔH°f(reactants)
Based on the given information, the ΔH°f of H2S(g) is -20.6, for Ag2S (s) is -32.6 and for H2O (l) is -285.8 kJ/mole.
Now putting the values we get,
= [2 molΔH°f (Ag2S) + 2 molΔH°f (H2O)] - [4 molΔH°f(Ag) + 2 molΔH°f(H2S) + 1 molΔH°f(O2)]
=[2 mol (-32.6 kJ/mol) + 2 mol(-285.8 kJ/mol)] - [4 mol(0.00 kJ/mol) + 2 mol (-20.6 kJ/mol) + 1 mol (0.00 kJ/mol)
= [(-65.2 kJ) + (-571.6 kJ)] - [(-41.2 kJ)]
= -595.6 kJ
Thus, the enthalpy change of -595.6 kJ takes place when 4 mol of Ag reacts by the equation mentioned.
The mass of Ag given is 6.38 grams, the molecular mass of Ag is 107.9 g/mol. The formula for calculating moles is,
Moles = mass/molar mass
= 6.38 g / 107.9 g/mol
= 0.0591 mol
Now the change in enthalpy when 0.0591 mol of Ag reacts by the given reaction is (-595.6 kJ/4 mol) × 0.0591 mol = -8.80 kJ
The negative sign indicates that the heat is released in the process. Therefore, the -8.80 kJ of heat is released by 6.38 grams of Ag in the given case.
When silver nitrate is added to an aqueous solution of magnesium chloride, a precipitation reaction occurs that produces silver chloride and magnesium nitrate. When enough AgNO3 is added so that 34.3 g of MgCl2 react, what mass of the AgCl precipitate should form
Answer:
103.62 g of AgCl.
Explanation:
Step 1:
The balanced equation for the reaction. This is given below:
2AgNO3 + MgCl2 —> 2AgCl + Mg(NO3)2
Step 2:
Determination of the mass of MgCl2 that reacted and the mass of AgCl produced from the balanced equation.
This is illustrated below:
Molar mass of MgCl2 = 24 + (2x35.5) = 95 g/mol
Mass of MgCl2 from the balanced equation = 1 x 95 = 95 g
Molar mass of AgCl = 108 + 35.5 = 143.5 g/mol
Mass of AgCl from the balanced equation = 2 x 143.5 = 287 g
Thus, from the balanced equation above,
95 g of MgCl2 reacted to produce 287 g of AgCl.
Step 3:
Determination of the mass of AgCl produced from the reaction of 34.3 g of MgCl2.
The mass of AgCl produced from the reaction can be obtained as follow:
Form the balanced equation above,
95 g of MgCl2 reacted to produce 287 g of AgCl.
Therefore, 34.3 g of MgCl2 will react to produce = (34.3 x 287)/95 = 103.62 g of AgCl.
Therefore, 103.62 g of AgCl were produced from the reaction.
What is an example of a molecular compound
Answer:
Molecular compounds are inorganic compounds that take the form of discrete (covalent) molecules. Examples include such familiar substances as water (H2O) and carbon dioxide (CO2).
A crystal lattice formed by positive and negative ions is called a
Answer:
Ionic Crystal
Explanation:
Using the periodic table provided, identify the atomic mass of sodium (Na) . Your answer should have 5 significant figures. Provide your answer below: __ amu
Answer:
Your answer will either be 22.9897 or 22.990 !!
Explanation:
Content attribution
QUESTION 2 • 1 POINT
Which anion would bond with K+ in a 1: 1 ratio to form a neutral ionic compound?
The given question is incomplete. The complete question is :
Which anion would bond with K+ in a 1: 1 ratio to form a neutral ionic compound?
a) [tex]O^{2-}[/tex]
b) [tex]F^{-}[/tex]
c) [tex]N^{3-}[/tex]
d) [tex]S^{2-}[/tex]
Answer: b) [tex]F^{-}[/tex]
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Here potassium is having an oxidation state of +1 called as cation and thus is an anion must have an oxidation state of -1 if they have to combine in 1: 1 ratio to give neutral ionic compound.
Thus the anion has to be [tex]F^-[/tex] which combines with [tex]K^+[/tex] in 1: 1 ratio to give [tex]KF[/tex]
Which Group is in the second column of the periodic table?
A. Noble gases
B. Halogens
C. Alkali metals
D. Alkaline earth metals
Answer:
Hey there!
That would be the alkaline earth metals.
Hope this helps :)
Answer: alkaline earth metals
Explanation:
Which phase change is an example of an exothermic process?
A.
solid to liquid
B.
solid to gas
C.
liquid to solid
D.
liquid to gas
E.
solid to plasma
Reset
Answer:
C
Explanation:
Turning liquid to a solid is like freezing water to ice and requires the water to LOSE (release) heat causing an exothermic reaction.
The Lucas test has _______ results based on the type of alcohol present because the reaction involves a _________, which is ________ stable for tertiary alcohols compared to primary alcohols. Therefore, tertiary alcohols react ________ primary alcohols.
Answer:
1) positive
2) carbocation
3) most stable
4) faster
Explanation:
A common test for the presence of alcohols can be achieved using the Lucas reagent. Lucas reagent is a mixture of concentrated hydrochloric acid and zinc chloride.
The reaction of Lucas reagent reacts with alcohols leading to the formation of an alkyl chloride. Since the reaction proceeds via a carbocation mechanism, tertiary alcohols give an immediate reaction. Once a tertiary alcohol is mixed with Lucas reagent, the solution turns cloudy almost immediately indicating an instant positive reaction.
Secondary alcohols may turn cloudy within five minutes of mixing the solutions. Primary alcohols do not significantly react with Lucas reagent obviously because they do not form stable carbocations.
Therefore we can use the Lucas reagent to distinguish between primary, secondary and tertiary alcohols.
Calculate the amount of HCl in grams required to react with 3.75 g of CaCO3 according to the following reaction: CaCO3(s) + 2 HCl(aq) → CaCl2(aq) + H2O(l) + CO2(g)
Answer:
The correct answer is 2.75 grams of HCl.
Explanation:
The given balanced equation is:
CaCO₃ (s) + 2HCl (aq) ⇒ CaCl₂ (aq) + H₂O (l) + CO₂ (g)
Based on the given information, one mole of calcium carbonate is reacting with two moles of HCl. The molecular mass of HCl is 36.5 grams, thus, the mass of 2 moles of HCl will be, 36.5 × 2 = 73 grams
The molecular mass of CaCO₃ is 100 gram per mole, that is, the mass of 1 mole of CaCO₃ is 100 grams, therefore, the mass of HCl required for reacting with 3.75 grams of CaCO₃ will be,
= 3.75 × 2 × 36.5 / 100 = 2.74 grams of HCl.
which statement describes the use of a flowchart?
Answer:
A flowchart is a type of diagram that represents a workflow or process
Explanation:
Answer: orders in which steps in a process happen
Explanation:
Convert the following measurement
Answer:
6.9 Kg/mol•dL
Explanation:
To convert 6.9×10⁴ g/mol•L to kg/mol•dL,
First, we shall convert to kg/mol•L.
This can be achieved by doing the following:
Recall: 1 g = 1×10¯³ Kg
1 g/mol•L = 1×10¯³ Kg/mol•L.
Therefore,
6.9×10⁴ g/mol•L = 6.9×10⁴× 1×10¯³
6.9×10⁴ g/mol•L = 69 Kg/mol•L
Finally, we shall convert 69 Kg/mol•L to Kg/mol•dL.
This is illustrated below:
Recall: 1 L = 10 dL
1 Kg/mol•L = 1×10¯¹ Kg/mol•dL
Therefore,
69 Kg/mol•L = 69 × 1×10¯¹
69 Kg/mol•L = 6.9 Kg/mol•dL
Therefore, 6.9×10⁴ g/mol•L is equivalent to 6.9 Kg/mol•dL.
A 45.0 mL sample of 0.020 M acetic acid (HC2H3O2) is titrated with 0.020 M NaOH.? Determine the pH of the solution after adding 35.0 mL of any NaOH. (Ka of acetic acid is 1.8 x 10-5) HC2H3O2 (aq) + NaOH (aq) D NaC2H3O2(aq) + H2O (l) (Hint: Calculate new concentration and ICE table)
Answer:
Explanation:
CH₃COOH + NaOH = CH₃COONa + H₂O .
.02M
CH₃COOH = CH₃COO⁻ + H⁺
C xC xC
Ka = xC . xC / C = x² C
1.8 x 10⁻⁵ = x² . .02
x² = 9 x 10⁻⁴
x = 3 x 10⁻²
= .03
concentration of H⁺ = xC = .03 . .02
= 6 x 10⁻⁴ M , volume = 45 x 10⁻³ L
moles of H⁺ = 6 X 10⁻⁴ x 45 x 10⁻³
= 270 x 10⁻⁷ moles
= 2.7 x 10⁻⁵ moles
concentration of NaOH = .0200 M , volume = 35 x 10⁻³ L
moles of Na OH = 2 X 10⁻² x 35 x 10⁻³
= 70 x 10⁻⁵ moles
=
NaOH is a strong base so it will dissociate fully .
there will be neutralisation reaction between the two .
Net NaOH remaining = (70 - 2.7 ) x 10⁻⁵ moles
= 67.3 x 10⁻⁵ moles of NaOH
Total volume = 45 + 35 = 80 x 10⁻³
concentration of NaOH after neutralisation.= 67.3 x 10⁻⁵ / 80 x 10⁻³ moles / L
= 8.4125 x 10⁻³ moles / L
OH⁻ = 8.4125 x 10⁻³
H⁺ = 10⁻¹⁴ / 8.4125 x 10⁻³
= 1.1887 x 10⁻¹²
pH = - log ( 1.1887 x 10⁻¹² )
= 12 - log 1.1887
= 12 - .075
= 11.925 .
Which functional group does the molecule below have?
A. Ether
B. Ester
C. Hydroxyl
D. Amino
Answer:
Hydroxyl
Explanation:
A hydroxyl group is a functional group that attaches to some molecules containing an oxygen and hydrogen atom, bonded together. Also spelled hydroxy, this functional group provides important functions to both alcohols and carboxylic acids.
The functional groups are the part of the organic chemistry that confers the characteristic feature of a molecule. The molecule has a hydroxyl group in its structure. Thus, option C is correct.
What are hydroxyl functional groups?Hydroxyl functional groups are the atoms or molecules that provide a distinctive property to a compound. It has a chemical formula of -OH that has oxygen covalently bonded to the hydrogen atom.
The hydroxyl group is called the alcohol group that is seen in methanol, ethanol, propanol, etc. The presence of hydrogen allows the compound to form a water bond with other molecules and makes them soluble and polar.
Therefore, option C. the molecule has a hydroxyl or alcoholic functional group attached to its carbon atom.
Learn more about the hydroxyl functional group here:
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g If you have three identical containers (same volume) at the same temperature and pressure, each with a different gas. Container A has He, container B has Ne, and container C has O2. Which flask contains the largest number of molecules? Group of answer choices
Answer:
The three gases, in the three identical containers, will all have the same number of molecules
Explanation:
If these three gases (Helium He, Neon Ne, and Oxygen [tex]O_{2}[/tex]) are all contained in separate identical containers with the same volume. And they are all stored at the same temperature, and pressure. Then, they'll all contain the same number of molecules. This is in line with Avogadro's law which states that "Equal volume of all gases, at the same temperature and pressure, have the same number of molecules."
bleaching powder reaction, mechanism, use
Answer:
Bleaching Powder's chemical formula is CaOCl2 and is called Calcium Oxychloride. It is prepared on dry slaked lime by chlorine gas. 2. ... It gives calcium chloride, chlorine and water when bleaching powder reacts with hydrochloric acid.
Explanation:
Calculate the maximum volume in mL of 0.18 M HCl that a tablet containing 340 mg Al(OH)3 and 516 mg Mg(OH)2 would be expected to neutralize. Assume complete neutralization.
Answer:
171 mL of HCl
Explanation:
The first thing we want to do is consider the reaction between Al(OH)3 and water - as that is the expected reaction that is taking place,
Al(OH)3 + 3HCl → AlCl3 + 3H2O
Knowing this, let's identify the mass of Al(OH)3. Aluminum = 27 g / mol, Oxygen( 3 ) = 16 [tex]*[/tex] 3 = 48, Hydrogen ( 3 ) = 1 [tex]*[/tex] 3 = 3 - 27 + 48 + 3 = 78 g / mol. This value is approximated however ( 78 g / mol ), as the molar mass of each substance is rounded as well. Another key thing we need to do here is to convert 340 mg → grams, considering that that unit is a necessity with respect to moles, as you might know - 340 mg = 0.340 g.
Now we can calculate how much moles of HCl will be present in solution, provided we have sufficient information for that,
(0.340 g Al(OH)3) / (78.0036 g / mol Al(OH)3) [tex]*[/tex] (3 mol HCl / 1 mol Al(OH)3)
⇒ (.004358773185 g^2 / mol Al(OH)3) [tex]*[/tex] (3 HCl / Al(OH)3 )
⇒ .01307632 mol HCl
We can apply this same concept on the reaction of Mg(OH)2 and water, receiving the number of moles of HCl when that takes place. Then we can add the two ( moles of HCl ) and divide by the value " 0.18 mol / L " given to us.
" Mg(OH)2 + 2HCl → MgCl2 + 2H2O "
Molar mass of Mg(OH)2 = 58.3197 g / mol,
516 mg = 0.516 g
(0.516 g Mg(OH)2) / (58.3197 g / mol Mg(OH)2) [tex]*[/tex] (2 mol HCl / 1 mol Mg(OH)2)
= .017695564 mol HCL
___________
( .01307632 + .017695564 ) / ( 0.18 M HCl )
= 0.170954911 L
= 171 mL of HCl
Which of the following metals has a low melting point?
2 A. Rubidium
B. Potassium
C. Calcium
D. Sodium
Answer:
Rubidium
Explanation: