Answer: There are 1.78 moles in 40.0 L of He gas at STP
Explanation:
According to ideal gas equation:
[tex]PV=nRT[/tex]
P = pressure of gas = 1 atm (STP)
V = Volume of gas = 40.0 L
n = number of moles = ?
R = gas constant =[tex]0.0821Latm/Kmol[/tex]
T =temperature =[tex]273K[/tex] (STP)
[tex]n=\frac{PV}{RT}[/tex]
[tex]n=\frac{1atm\times 40.0L}{0.0821Latm/K mol\times 273K}=1.78moles[/tex]
Thus there are 1.78 moles in 40.0 L of He gas at STP
1. How is extinction different from mass extinction?
Answer:
Extinction is the elimination of one species whereas mass extinction results in multiple animals to become extinct.
When 1 mol of Zn reacts with 0.8 mol of HCI, which of the following will be true?
Answer:
Zn is the excess reagent
Explanation:
What is the acid dissociation constant for an acid at equilibrium, HX = H+ +X- ?
Ka = [H+] [X-] ÷ [HX] is the acid dissociation constant for an acid at equilibrium.
What is chemical equilibrium?Chemical equilibrium is the condition in which no net change in the amounts of reactants and products occurs.
HX(aq) ↔ H+(aq) + X-(aq)
[H+] = [X-]
Ka = [H+] [X-] ÷ [HX]
Hence, Ka = [H+] [X-] ÷ [HX] is the acid dissociation constant for acid at equilibrium.
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Add the missing words !! (Provided is the lines and it signifies the number of words) 1.) It is the composition of all compounds -> _ _ _ _ _ 2.) It describes the crystals of ionic solids -> _ _ _ _ _ 3.) What is shared unequally in a polar bond? -> _ _ _ _ _ _ _ _ 4.) Number of shared electrons in N2 -> _ _ _ 5.) What happens to electrons in the formation of ionic bonds? -> _ _ _ _ _ _ _ _ 6.) What are these intermolecular forces that caused low melting and boiling points? -> _ _ _ _ 7.) What must be added to break bonds? -> _ _ _ _ _ _
Answer:
1. Atoms
3. Electrons
4. 3 pairs
5. Complete transfer of electrons
6. London dispersion forces
7. Energy
Explanation:
Atoms are the building block from which a compound is formed so we can say that composition of compounds depends on type of atoms. Electrons are shared unequally in a polar bond due to difference in electronegativity values of bonded atoms. There are 3 pairs of electrons are shared in nitrogen molecule. The transfer of electrons occurs from one atom to another in the formation of ionic bonds. London dispersion forces are the intermolecular forces that is responsible for the low melting and boiling points of a molecule or compound. Energy is needed to break the bonds that is present between the two bonded atoms.
HELP ASAP!!!!
Identify each substance as a molecular compound or an
ionic compound, and then calculate its molar mass.
a. Sr(NO3)2
b. (NH)3PO4 C. C12H22O11
Answer:
a. ionic, 211.62g/mol
b. molecular, 149g/mol
c. molecular, 342g/mol
Explanation:
Ionic Compound: These are compounds (2 or more elements) where atoms of the element have lost or gained electrons, thus they are ions, thus the name ionic. An easy way to identify ionic compounds is to see if there are any metals. Metals tend to give up their electron to a non-metal. It maybe helpful to familiarize which parts of the periodic table have metals and non-metals.
Molecular Compounds: These are compounds (2 or more elements) that are neutral. An easy way to identify them is that the compound is made up of just non-metals.
Molar Mass is the masses of each individual element in the compound. Refer to the periodic table for the masses and add them up carefully, remember to multiply their mass based on how many molecules there are in the compound, like for a, we can find the mass of NO3, but we need to multiply it by 2 since we have 2 molecules of NO3.
a. Sr(NO3)2
Sr= 87.62
NO3= 14 + (3 x 16)= 62
Sr + 2 (NO3)
87.62 + (2 x 62)= 211.6
b. (NH4)3PO4
NH4= 14 + 4 = 18
PO4= 30.97 + (4 x 16)= 94.9
(NH4 x 3) + PO4
(18 x 3) + 94.9 = 149
c. C12H22O11
(12 x C) + (22 x H) + (11 x O)
(12 x 12) + (22 x 1) + (11 x 16)
144 + 22 + 176= 342
Lithium nitride LiN LiN3 Li3N
Answer:
Li3N
Explanation:
Lithium nitride is a compound with the formula Li₃N
Hope this helped!!!
Answer:
C
the next answer is B
the next one is C
Explanation:
3. Components in a heterogeneous mixture are not in the same phase or the composition of the mixture is
a) uniform
b) transparent
c) uneven
4. Mixing sand and salt in water then passing it through a filter separates out the sand because salt
in water and sand does not.
a) reacts
b) dissolves
c) disappears
Answer:
c
Explanation:
H2SO4 + 2 NaOH →
Na2SO4 + 2 H20
What mass of H2SO4 would be required to react with 2.25 mol of NaOH?
Answer:
110.25grams
Explanation:
The balanced chemical equation is as follows:
H2SO4 + 2NaOH → Na2SO4 + 2H20
Based on the balanced chemical equation of the reaction given above, 1 mole of sulphuric acid (H2SO4) is required to react with 2 moles of sodium hydroxide (NaOH).
Hence, if 1 mol of H2SO4 is needed to react with 2 moles of NaOH
Then, 2.25mol of NaOH will be required to react with;
= 2.25/2
= 1.125mol of H2SO4
Using the formula, mole = mass/molar mass, we can convert the molar value of H2SO4 to its mass value.
Molar mass of H2SO4 = 1(2) + 32 + 16(4)
= 2 + 32 + 64
= 34 + 64
= 98g/mol
Therefore, mole = mass/molar mass
1.125 = mass/98
mass = 98 × 1.125
mass = 110.25grams of H2SO4
Which statement correctly describes a solution
with a pH value of 10?
a. It would turn litmus red.
b. It would turn methyl orange red.
c. It would turn thymol blue yellow.
d. It would turn phenolphthalein pink.
Answer:
d. It would turn phenolphthalein pink.
Explanation:
A sample of gas has a pressure of 100.0 KPa and 25C. Calculate the pressure if the temperature is changed to 125C while the volume remains constant.
Answer:
133.56kPa
Explanation:
Applying Pressure Law,
P/T = P'/T'....................... Equation 1
Where P = Initial pressure, T = Initial Temperature, P' = Final pressure, T' = Final Temperature.
From the question, we were asked to calculate P'
There, we make P' the subject of the equation
P' = PT'/T...................... Equation 2
Given: P = 100kPa, T = 25°C = (273+25) = 298K, T' = 125°C = (273+1250K = 398 K
Substitute these values into equation 2
P' = (100×398)/298
P' = 133.56kPa
Hence the pressure is 133.56kPa
what is the oceanic and continental crust made out of ?
Answer:
Oceanic crust is generally composed of dark-colored rocks called basalt and gabbro. It is thinner and denser than continental crust, which is made of light-colored rocks called andesite and granite. The low density of continental crust causes it to “float” high atop the viscous mantle, forming dry land.
Explanation:
What is the complete ionic equation for Hydrochloric acid and sodium hydroxide
Hydrochloric acid: HCl(aq)
Sodium hydroxide: NaOH(aq)
The two substances react in an acid-base neutralization reaction to produce aqueous sodium chloride and liquid water.
The complete ionic equation is:
H⁺(aq) + Cl⁻(aq) + Na⁺(aq) + OH⁻(aq) → Na⁺(aq) + Cl⁻(aq) + H₂O(l).
mass of 12 helium atom
plz help me.....im new here
Answer:
Fe2S3
Explanation:
Answer:
Option 3rdFe2S3
Explanation:
As, the ionic valency of Iron (Fe) that is + 3 interchanges with the ionic valency of Sulphide that is - 2 to form-
Fe2S3
In a single carbon bond, two carbon atoms share
pair of electrons.
Answer:
C-C
A carbon has 4 valence electrons meaning it can share 4 electrons and is in short of 4 electrons to fill it outer energy shell making it 8. Which results to 2 double covalent bonds ,meaning there was a sharing of 2(4) = 8 electrons . Hope this helps . Your statement above is true .
Assuming that the trends continue, which of the following compound will have the greatest solubility at 120 ℃? The graph below shows the solubility of a variety of compounds.
A. Ce2(SO4)3
B. K2Cr2O7
C. NaCl
D. Pb(NO3)2
Answer:
its c
Explanation:
i took the test and got a 100
Assuming that the trends continue, sodium chloride compound will have the greatest solubility at 120 ℃.
What is solubility?Solubility is defined as the ability of a substance which is basically solute to form a solution with another substance. There is an extent to which a substance is soluble in a particular solvent. This is generally measured as the concentration of a solute present in a saturated solution.
The solubility mainly depends on the composition of solute and solvent ,its pH and presence of other dissolved substance. It is also dependent on temperature and pressure which is maintained.Concept of solubility is not valid for chemical reactions which are irreversible. The dependency of solubility on various factors is due to interactions between the particles, molecule or ions.
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How many atoms of aluminium are contained in 2.75 mol
1.66 × 10²⁴ atoms Al
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TableMolesAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Stoichiometry
Using Dimensional AnalysisExplanation:Step 1: Define
[Given] 2.75 mol Al
[Solve] atoms Al
Step 2: Identify Conversions
Avogadro's Number
Step 3: Convert
[DA] Set up: [tex]\displaystyle 2.75 \ mol \ Al(\frac{6.022 \cdot 10^{23} \ atoms \ Al}{1 \ mol \ Al})[/tex][DA] Multiply [Cancel out units]: [tex]\displaystyle 1.65605 \cdot 10^{24} \ atoms \ Al[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
1.65605 × 10²⁴ atoms Al ≈ 1.66 × 10²⁴ atoms Al
Help, please :)
What type of bond is being shown here?
A. Single covalent
B. Double covalent
C. Triple covalent
D. None
Answer:
Double bond, Double Covalent
Explanation:
Hope this helps!
Raise the temperature of 2 g of water 2°C.
Answer:
This heat requirement we can calculate by following relationship..
Q = m*C*∆T
We have, m = 2gm, C = 1 cal/g-degC, ∆T = 2 degC
Putting all these values in above equation we get
Q= 2*1*2 = 4 cal
A balloon has a volume of 5.0 L at a pressure of 0.863 atm. What is the volume of the balloon in
liters if the atmospheric pressure is reduced to 0.321 atm?
Answer:
V₂ = 13.44 L
Explanation:
Given that,
Initial volume, V₁ = 5 L
Initial pressure, P₁ = 0.863 atm
Final pressure, P₂ = 0.321 atm
We need to find the final volume of the balloon. The relation between the volume and pressure is given by :
[tex]P_1V_1=P_2V_2[/tex]
Where
V₂ is the volume of the balloon
So,
[tex]V_2=\dfrac{P_1V_1}{P_2}\\\\V_2=\dfrac{0.863 \times 5}{0.321 }\\\\V_2=13.44\ L[/tex]
So, the final volume of the balloon is equal to 13.44 L.
WILL GIVE BRANLIEST!! EASY BUT I WAS TO LAZY TO LEARN!! WILL FOREVER BE GREATFUL!!!
2. Which type of solution below has a cloudy appearance? (Choose all that apply)
A) Alloys
B) Solutions
C) Colloids
D) Suspensions
4. What is the difference between a primitive and body centered unit cell?
Answer:
b and In a primitive unit cell, particles or points are present only at the corners while in a centred unit cell, the particles or points are also present at other positions in addition to the corner
Explanation:
when pressure is kept constant then the temperature varies with volume
a. directly
b. inversely
c. none of these
d. both a and b.
Answer:
A
Explanation:
density is the ratio of mass per unit volume. fact or bluff
Answer:
Fact
Explanation:
K/U_____ /13 T/I______/5
Knowledge and Understanding
1. Complete the following chart: [9 Marks]
Name (1 mark each)
Formula
Type of Compound (Ionic or Molecular) (1/2 mark each)
Diphosphorus Pentoxide
CBr4
Li2O
Silicon Dioxide
CH4 (Write the common name)
Manganese (III) Fluoride
Answer:
it shouuld be the third one down c
Explanation:
Calculate the [H3O+] of an aqueous solution that is 1.94 x 10-7 Min OH.
Enter your answer in scientific notation. Be sure to answer all parts.
_x 10^_M
What is one definition of a base?
O A. A substance that increases the hydroxide ions in a solution
B. A substance that forms a salt when it dissolves in water
O C. A substance that stops the flow of electrons when dissolved
O D. A substance that makes the pH of a solution more acidic
Answer:
the answer is A
Explanation:
The base increases Hydroxide ions in a solution e.g NaOH
Answer:
A
Explanation:
Which equation represents a fusion reaction?
Please answer asap
(Look at picture)
Answer:c
Explanation:
If you have 5 moles of carbon dioxide at 30degrees C and under 600mmHg of pressure, what will the volume be
Answer:
157.64 L
Explanation:
We'll begin by converting 30 °C to Kelvin temperature. This can be obtained as follow:
T(K) = T(°C) + 273
T(°C) = 30 °C
T(K) = 30 °C + 273
T (K) = 303 K
Next, we shall convert 600 mmHg to atm. This can be obtained as follow:
760 mmHg = 1 atm
Therefore,
600 mmHg = 600 mmHg × 1 atm / 760 mmHg
600 mmHg = 0.789 atm
Finally, we shall determine the volume of the gas. This can be obtained as follow:
Number of mole (n) = 5 moles
Temperature (T) = 303 K
Pressure (P) = 0.789 atm
Gas constant (R) = 0.0821 atm.L/Kmol
Volume (V) =?
PV = nRT
0.789 × V = 5 × 0.0821 × 303
0.789 × V = 124.3815
Divide both side by 0.789
V = 124.3815 / 0.789
V = 157.64 L
Therefore, the volume of the gas is 157.64 L
Now balance the chemical
reaction by providing the correct
whole number coefficients:

Answer:
2(C4H10)+13(O2)->8(CO2)+[](H20)
Explanation:
sorry i couldn’t get the last one
The chemical reaction by providing the correct whole number coefficients: number coefficients will be 2C4H10 + 13O2 WILL GIVE 8CO2 + 10H2O .this will be the balanced reaction.
What is the balanced reaction?Balance elements in the equation other than O and H. Balance the oxygen atoms by adding the appropriate number of water ( H 2O) molecules to the opposite side of the equation.
Balance the hydrogen atoms (including those added in step 2 to balance the oxygen atom) by adding H + ions to the opposite side of the equation.
When writing an equation for a chemical reaction, the two sides of the equation should balance and need the same number of each kind of element on both sides.
Therefore the given chemical equation is balanced in the following form, 2C4H10 + 13O2 WILL GIVE 8CO2 + 10H2O
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Can someone help me plss
Answer:
the 3rd option is correct I promise
Explanation:
matter can not be created or destroyed no matter what, most important rule is chemistry