Answer:
La mea vola weon
Explanation: Tu mai es zoerrra
What type of solid consists of positive metal cations surrounded by valence electrons that
are donated by the metal atoms and belong to the solid as a whole?
Select one:
O a. ionic
O b. covalent network
O c. metallic
O d. covalent molecular
What is the pH of a solution that has [OH-] = 4.0 x 10-'M?
Answer: 13.60
Explanation:
[tex]\frac{10^{-14} }{4.0 x 10^{-} }[/tex] = 2.5 x10^-14 this =[tex][H_{3} O^{+} ][/tex]
pH = -log[tex][H_{3}O^{+} ][/tex]
pH= -log( 2.5 x10^-14) = 13.60
Which would cause an electric circuit to lack a current?
open switch
closed switch
lighted bulbs
unlighted bulbs
Answer:
A) open switch
Explanation:
it is an open switch, seeing that when the switch is open, there is a gap between the wire and switch preventing any electric current from flowing. A closed switch is the opposite.
The flow of current is needed to be circuit closed. The electrons are starts following form one end to other end. The lack of current in the circuit is due to open switch.
What is current?Current is said to be the flow of electrons in an electric circuit. The electrons starts flow is mainly due to potential difference.
Current is represented by I.
SI unit of current is Ampere.
In home, the circuit is designed in such a way that, the flow of electricity is controlled by switch. If switch is off mode, there is no electricity flow and glow light or electrical application.
Voltage is the difference in electric potential between two points. Current is just the rate of flow of electric charge.
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crossover formula of potassium oxide.
Answer:
K2O
Explanation:
It carries the chemical formula K2O. Potassium cannot be found free because it is too reactive. It has valency +1 and combines readily with oxygen atoms forming K2O.
hope it helps
Read the two passages. Silicon is an element that is directly below carbon on the periodic table. Silicon can form bonds similar to carbon. Silicon-silicon single bonds require 222 kJ/mol of energy to break. Based on the statements, how much energy would it take to break a carbon-carbon single bond?
Answer:
100kj/mol
Explanation:
the reaxtion between calcium and nitrogen to form calcium nitride is a redox reaction.
In terms of electrons, explain why calcium is the reducing agent.
which of the following is a characteristic of a weak acid? A. It does not conduct electricity in water B. It is not as dangerous as a strong acid C. It is less concentrated than a strong acid D. It does not dissociate completely in water
Answer:
A B C D (all of the above)
Explanation:
Weak acid do not have a much hydrogen ions when in liquids or aqueous solutions. Examples of weak acids include vinegar, citric acid (from oranges, lemons, etc)
how many molecules of water are present in a 5.65 mole sample of water
Answer:
5.65
Explanation:
A solution of Cuso, is labelled 1.743 M. How much Cuso, in grams, must be used to make
1.4957 liter of solution?
Select one:
O a. 416.1
Ob. 0.007301
O c. 166.6
Od. 129.2
Answer:
Option A. 416.1 g.
Explanation:
Data obtained from the question include the following:
Molarity = 1.743 M
Volume = 1.4957 L
Mass of CuSO4 =..?
Next, we shall determine mole of CuSO4 present in the solution.
This is illustrated below:
Molarity is simply defined as the mole of solute per unit litre of the solution. Mathematically, it is expressed as:
Molarity = mole /Volume
With the above formula, we can obtain the mole CuSO4 present in the solution as follow:
Molarity = 1.743 M
Volume = 1.4957 L
Mole of CuSO4 =..?
Molarity = mole /Volume
1.743 = mole of CuSO4 /1.4957
Cross multiply
Mole of CuSO4 = 1.743 x 1.4957
Mole of CuSO4 = 2.607 moles
Finally, we shall convert 2.607 moles of CuSO4 to grams.
This can be obtained as follow:
Molar mass of CuSO4 = 63.55 + 32.06 + (16x4) = 159.61 g/m
Mole of CuSO4 = 2.607 moles
Mass of CuSO4 =..?
Mole = mass /molar mass
2.607 = mass of CuSO4 /159.61
Cross multiply
Mass of CuSO4 = 2.607 x 159.61
Mass of CuSO4 = 416.1 g
Therefore, 416.1 g of CuSO4 is needed to prepare the solution.
which of the following reaction would result in a decrease in entropy?
Answer:
C
Explanation:
For each reaction, compare molecules of reactant to molecules of product. Decrease entropy means I'm looking for the one that decreases.
Hellppp Ethanol, an organic compound, has the following structural formula.
Hн
Н-С-С-0—Н
1
Hн
What is the chemical formula of Ethanol
Ch6o
C2H5O
C2H5O
C2H6O6
Answer:
D) C2H6O
Explanation:
structural formula for ethanol is :
C2H5OH or C2H6O
Answer:
[tex]\boxed{\sf C_2 H_6 O}[/tex]
Explanation:
The structural formula of ethanol is given.
There are 2 carbon atoms, 6 hydrogen atoms, and 1 oxygen atom.
The molecular formula of ethanol is [tex]{\sf C_2 H_6 O}[/tex].
A gaseous substance turns directly into a solid. Which term describes this change?
O deposition
O evaporation
O melting
O sublimation
Answer:
deposition
Explanation:
Sublmation- solid transforming into a gas, skipping the liquid stage.
eveporation- a liquid transformimg into a gas
melting- a solid transforming into a liquid
deposition- the opposite of sublimation (your anwser)
A gaseous substance turns directly into a solid. The term which is indicative of this change is deposition.
Evaporation is a process in which a liquid which when exposed to heat boils and converted into vapors of water. For example, the water is converted into water vapors. Melting is a process in which the solid substance when exposed to heat melts . In this a solid is converted into liquid. For example, a solid ice is melted into liquid. Sublimation is a process in which a solid is converted into a vapor state without being converted into a liquid. For example, dry ice in which the solid dry ice is converted into vapors in presence of air. Deposition is the process in which gaseous molecules aggregate and combine to form a solid. It is opposite of sublimation process. For example, conversion of water vapors to ice.Hence, deposition is the correct option.
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Convert the pressure 525.4 torr to kPa.
Select one:
O a. 70.0
Ob. 3940
O c. 9.90
Od. 525
Answer:
Option A. 70.0 KPa.
Explanation:
Data obtained from the question include:
Pressure (torr) = 525.4 torr
Pressure (kPa) =?
The pressure expressed in torr can be converted kPa as shown below:
760 torr = 101.325 KPa
Therefore,
525.4 torr = (525.4 x 101.325) / 760 = 70.0 KPa.
Therefore, 525.4 torr is equivalent to 70.0 KPa.
Calculate the amount of 0.1 M acid needed to neutralize 10,000 liters of pH 8.0 water. The acid is Sulfuric Acid - H2SO4 Show your work for brainliest
Answer:
0.963
Explanation:
pH is the potential of hydrogen that can be determined by the hydrogen or hydroxide ion concentration. 10 mL is the amount required of 0.1 M to neutralize.
What is pH?pH estimates the acidic and the basicity of the solution when a solute is dissolved in the solvent.
Sulfuric acid is dissociated as:
H₂SO₄(aq) ⇌ H⁺(aq) + HSO₄⁻(aq)
pH is calculated as:
pH = -log [H⁺]
[H⁺] = 1x10⁻⁸ M
The moles in 10,000 L is, 10000L × 1x10⁻⁸ = 0.0001 moles
Moles of sulfuric acid required:
0.0001 moles × ( 1 mol H2SO4 ÷ 1 mol H⁺) = 0.001 moles
Further, volume is calculated as:
0.001 × (1L ÷ 0.1moles) = 0.01 L
Therefore, 10 mL of 0.1 M acid is needed to neutralize.
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For the reaction C + 2H2 - CH2, how many moles of hydrogen are required to produce
19.26 mol of methane, CHA?
Select one:
O a. 19.26
O b. 38.52
O c. 15.0
O d. 24.7
Answer: 38.52 moles of hydrogen will be required to produce 19.26 mol of methane
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of} CH_4=19.26moles[/tex]
The balanced chemical reaction is:
[tex]C+2H_2\rightarrow CH_4[/tex]
According to stoichiometry :
1 mole of [tex]CH_4[/tex] is produced by = 2 moles of [tex]H_2[/tex]
Thus 19.26 moles of [tex]CH_4[/tex] will be produced by =[tex]\frac{2}{1}\times 19.26=38.52moles[/tex] of [tex]H_2[/tex]
Thus 38.52 moles of hydrogen will be required to produce 19.26 mol of methane
Which of the following statements is true?
A Question Progress A
A. Factors that affect the reaction rate can increase the speed of a reaction but not the
yield.
O
B. None of these
C. Catalysts are important to industry to increase product yields
D. A reaction can be sped up by reducing the surface area of solid reactants.
Reset Selection
Answer:
c
Explanation: c
The statement that is true from the following is catalysts are important to the industry to increase product yields. The correct option is C.
What is a catalyst?Catalysts are substances that speed up or increase the rate of reaction. The biological catalysts are enzymes. Enzymes are made up of proteins, and they are used in the reaction to increase the yield in less time. Catalyst does not mix with the process and after the reaction.
There are many chemical catalysts like nickel and iron. These catalysts are used in chemical and manufacturing processes. They impact, accelerate, and promote the reaction to get different yields.
Thus, the correct option is C. Catalysts are significant to industry to increase product yields.
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Which of the following is NOT a reason atom economy is important?
A. Minimize waste of non-renewable reactants
B. To reduce the amount of water used in cooling reactions
C. Make as much product as possible
D. Increase energy use during reactions
Reset Selection
Answer:
Increase energy use during reactions
Explanation:
Answer via Educere/ Founder's Education
Increase energy use during reactions. Hence, option D is correct.
What is an atom?An atom is any particle of matter at its most basic level which contains at least one proton.
A reaction with a high atom economy is important in industry because it uses lesser natural resources, produces less waste, and is better for the environment. It is also cheaper to produce and more sustainable.
Increasing energy used during reactions is NOT a reason atom economy is important.
Hence, option D is correct.
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A reaction between ethene and oxygen is used to produce epoxyethane. When silver is combined with ethene, the reaction for producing epoxyethane occurs much faster. What role does silver play in this chemical process?
A. Silver is a catalyst in this reaction.
B. Silver is a p-type semiconductor in this reaction.
C. Silver causes hydrolysis in this reaction.
D. Silver is an n-type semiconductor in this reaction.
Answer:
A. Silver is a catalyst in this reaction.
Explanation:
The most common use of rare-earth metals is as catalysts in chemical reactions.
To solve such this we must know the concept of chemical reaction. Therefore, the correct option is option A that is Silver is a catalyst in this reaction.
What is chemical reaction?Chemical reaction is a process in which two or more than two molecules collide in right orientation and energy to form a new chemical compound. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, double displacement reaction.
A reaction between ethene and oxygen is used to produce epoxyethane. When silver is combined with ethene, the reaction for producing epoxyethane occurs much faster. Silver is a catalyst in this reaction.
Therefore, the correct option is option A that is Silver is a catalyst in this reaction.
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The temperature of a sample of gas at 8.5 atm and 59.2 °C increases to 140.0 °C. If the
volume is unchanged, what is the new gas pressure?
Select one:
O a. 10.6
Ob. 20.1
Oc. 6.84
Od. 119
Answer:
since that's the closest option we have
10.6atm
Explanation:
Since volume is constant
P1/T1 = P2/T1
P1 =8.5atm
T1 = 59.2°C = 332.2k
T2 = 140°C = 413k
P2 = ?
8.5/332.2 = P2/413
0.026 = P2/413
P2 = 0.026 x 413
P2 = 10.74atm
(02.05 HC)
A scientist observed a certain type of a particular bacteria growing in a substance that had a 1,000 times higher amount of the antibiotic that targets this bacteria. Using complete
sentences, justify the observation based on your knowledge of natural selection
Answer:
Para otros usos de este término, véase Resistencia.
La resistencia antibiótica es la capacidad de un microorganismo para resistir los efectos de un antibiótico. La resistencia se produce naturalmente por selección natural a través de mutaciones producidas por azar. El antibiótico, al entrar en contacto con una población bacteriana, permite solo la proliferación de aquellas bacterias que presentan aquella mutación natural que anula la acción del antibiótico. Una vez que se genera la información genética, las bacterias pueden transmitir los nuevos genes a través de transferencia horizontal (entre individuos) por intercambio de plásmidos; o igualmente producto de una conversión lisogénica. Si una bacteria porta varios genes de resistencia, se le denomina multirresistente o, informalmente, superbacteria.
A solar panel combines multiple photovoltaic cells. Which type of energy is used to power a solar panel?
Explanation:
Photovoltaic means electricity from light
photo = light voltaic = electricity
SUNLIGHT is the answer
Hope this is correct
HAVE A GOOD DAY!
What is the percent yield of lithium hydroxide from a reaction of 7.40g of lithium with 10.2g of water? The actual yield was measured to be 12.1g.
Answer:
[tex]\boxed{Percentage \ Yield = 47.6 \ percent}[/tex]
Explanation:
The balanced chemical reaction is
[tex]2Li + 2H_{2}O \ \ \ -> \ \ \ 2LiOH + H_{2}[/tex]
For the balanced reaction, we've
Lithium = 14 g
Water = 36 g
LiOH = 48 g
Hydrogen gas = 2 g
So,
14 g of lithium = 48 g of lithium hydroxide
And we have:
7.40 g of lithium = x grams of lithium hydroxide
Cross Multiplying,
x grams = [tex]\frac{48*7.4}{14}[/tex]
Grams of lithium = 25.4 g of lithium hydroxide
So, Theoretical Yield = 25.4 g of lithium hydroxide
Now, The %age yield:
%age Yield = [tex]\frac{Actual \ Yield}{Theoretical \ Yeild } * 100[/tex]
%age Yield = [tex]\frac{12.1}{25.4} * 100[/tex]
%age Yield = 47.6%
What is the molality of a solution that contains 418.8 g HCl in 4.62 kg water?
Select one:
O a 2.49
Ob. 0.00249
Oc. 15.3
Od.4.19e5
Answer:
a 2.49
Explanation:
Molality is a measure of concentration of solution which describes the number of moles of solute per kilograms of the solvent.
Molality (M) = number of moles of solute (n) / kg solvent
According to the question; mass of solute (HCl) = 418.8g, mass of solvent (water) = 4.62kg
To find the number of moles (n) of solute (HCl), we use; mass (g) / molar mass (g/mol)
Molar mass of HCl = 1 + 35.5 = 36.5g/mol
Hence, n= 418.8/36.5
n= 11.4739
n= 11.5
Therefore, Molality= 11.5 mol of HCl / 4.62kg of water
M= 11.5/4.62
M= 2.489
Hence, molality of the solution is 2.49
Convert the following numbers of calories or
kilocalories into joules or kilojoules.
a. 7845 cal
b. 4.55 x 104 cal
C. 62.142 kcal
d. 43,024 cal
Answer:
a. joules=32823480 , kilojoules=32823.48
b. joules=1979868.8 , kilojoules=1979.8688
c. joules=260002.128 , kilojoules=260.002128
d. joules=180012416 , kilojoules=180012.416
Explanation:
calories to kilo joules=multiply the energy value by 4.184
calories to joules=multiply the energy value by 4184
kilo calories to joules=multiply the energy value by 4184
kilo calories to kilo joules=multiply the energy value by 4.184
Which type of molecule is shown below?
Answer:
[tex]\boxed{\mathrm{Alkene}}[/tex]
Explanation:
The hydrocarbon shown has a double bond. Hydrocarbons with double bonds are known as alkenes.
Cyclic alkanes have cyclic structure.
Alkanes only have single bonds.
Alkynes have triple bonds.
Answer:
Alkene
Explanation:
A molecule having a double bond between its atoms is called an alkene.
1. Consider the following equilibrium system: C(s) + CO2(g) 2CO(g)
∆Hr° = +120 kJ
Indicate the shift in equilibrium, if any, for each of the following scenarios: a) Adding CO2(g) b) Adding C c) Lowering the temperature d) Increasing pressure e) Adding a catalyst
Answer:
a) equilibrium shifts towards the right
b) equilibrium shifts towards the right
c) equilibrium shifts towards the left
d) has no effect on equilibrium position
e) has no effect on equilibrium position
Explanation:
A reversible reaction may attain equilibrium in a closed system. A chemical system is said to be in a state of dynamic equilibrium when the rate of forward reaction is equal to the rate of reaction.
According to Le Chateliers principle, when a constraint such as a change in temperature, pressure, volume or concentration is imposed upon a system in equilibrium, the equilibrium position shifts in such a way as to annul the constraint.
When the concentration of reactants is increased, the equilibrium position is shifted towards the right hand side and more products are formed. For an endothermic reaction, the reverse reaction is favoured by a decrease in temperature. Increase in pressure has no effect on the system since there are equal volumes on both sides of the reaction equation. Similarly, the addition of a catalyst has no effect on the equilibrium position since it speeds up both the forward and reverse reactions to the same extent.
To what volume will a 2.33 L sample of gas expand if it is heated from 10.0°C to 100.0°C? Group of answer choices 0.233 L 4.41 L 23.3 L 3.76 L 3.07 L
Answer:
3.07 L
Explanation:
This question describes Charles law, which shows the direct relationship of the absolute temperature to its volume when the pressure is kept constant. The Charles' law equation is:
V1/T1 = V2/T2
Where; V1 is the volume of the gas at an initial state
V2 is the volume of the gas at a final state
T1 is the absolute temperature of the gas at an initial state
T2 is the absolute temperature of the gas at a final state.
According to the question, V1 = 2.33L, V2 = ?, T1 = 10°C, T2 = 100°C
The absolute temperature unit, which is Kelvin, need to be used. Hence, we convert °C to Kelvin using:
T(K) = T(°C) + 273.15
T1 (K) = 10°C + 273.15 = 283.15K
T2 (K) = 100°C + 273.15 = 373.15K
To solve for V2 in the above Charles law equation, we make V2 the subject of the formula by saying:
V2 = V1 × T2 / T1
V2 = 2.33 × 373.15 / 283.15
V2 = 869.4395/ 283.15
V2 = 3.0705
Hence, the gas will be expanded to a volume of 3.07L when heated from 10.0°C to 100.0°C.
Based on the electron configuration of the two
atoms, predict the ratio of metal cationic (+) atom
to nonmetal anionic (-) atom in the compound.
Lithium 1s²2s1
Nitrogen 1s22s22p3
Answer:
3:1
Explanation:
Lithium is a group 1 element. This means it would donate one electron to form the cation.
Nitrogen on the other hand is a group 5 element. It would accept 3 electrons to form the anion.
This means there has to be three lithium atoms, each donating an electron each to the nitrogen atom for a compound to be formed.
The formular for the ionic compound would be given as;
Li₃N
Hence the ration is 3:1
What causes hydrogen bonding?
bonding of a covalently bonded hydrogen atom with an unshared electron pair
motion of electrons
attraction between ions
sharing of electron pairs between two adjacent hydrogen atoms
Answer:
the tendency of some atoms in molecules to attract electrons more than their accompanying atom.
Explanation:
Consider the reaction below.
NH4 + H20 - NH3 + H30"
Which is an acid-conjugate base pair?
O NHA and NH3
O NH4" and H30*
O H20 and NH3
O H20 and H20"
Answer:
The correct ans is....
Option B) NH4" and H30*
Explanation:
NH4" and H30* is an example of conjugate pair
Hope this helps....
Pls mark my ans as brainliest :)PLS, PLS, PLSThe acid-conjugate base pair : ( B ) NH₄⁺ and H₃O⁻
The chemical reaction is
NH₄ + H₂O --> NH₃ + H₃O
Acid-conjugate base pairAn acid-conjugate base pair is a pair that consists of two substances that are different from each other just by the presence or absence of a proton ( H⁺ ) it helps to determine the relative strengths of acids and bases.
Hence we can conclude that the acid-conjugate base pair : ( B ) NH₄⁺ and H₃O⁻.
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