Empirical Formula and % Composition
Which compound has the empirical formula CH2O?
a. CH3OH
b. Ch3CH2OH
c. HCOOH
d. CH3COOH
a. CH3OH
Which diagram represents the most likely orientation of X2 and Z2 when the molecules collide with proper energy, [producing an activated complex?
B
You need proper orientation of collision and activation energy in order for a reaction to occur
A catalyst increases the rate of a chemical reaction by
a. lowering the activation energy of the reaction
b. lowering the potential energy of the products
c. raising the temperature of the reactants
d. raising the concentration of the reactants
a. lowering the activation energy of the reaction
As two chlorine atoms combine to form a molecule, energy is
a. absorbed
b. released
c. created
d. destroyed
Released
What is the molarity of KOH solution if it requires 20 mL of 2.0 M HCl to exactly neutralize 30 mL of the KOH solution?
a. 1.3 M
b. 2.0 M
c. 13 M
d. 20 M
a. 1.3
What is the empirical formula of the compound whose molecular formula is P4O10?
a. PO
b. PO2
c. P2O5
d. P8O20
c. P2O5
Which molecule is nonpolar and contains a nonpolar covalent bond?
a. CCl4b.
b. F2
c. HF
d. HCl
B
Given the reaction at equilibrium:
An increase in the concentration of O2 at constant temperature and pressure will result in
a. an increase in the concentration of CH4
b. an increase in the concentration of CO2
c. a decrease in the concentration of O2
d. a decrease in the concentration of H2O
b. an increase in the concentration of CO2
Which process increases the potential energy of the particles of a sample?
Vaporization
How many mL of 2.5 M HCl are required to exactly neutralize 15 mL of 5.0 M NaOH?
30
Question 18
C2H3O2
On the baord - draw the Electron Dot Diagram (Lewis Dot Structure) for Nitrogen
:)
Explain the difference between endothermic and exothermic
Endothermic - absorb heat
Exothermic - expels heaet
Identify a line segment in which the average kinetic energy is increased
AB, CD, EF
What will be the new volume of a 1.00-mole sample of a gas at STP if the pressure remains constant and the Kelvin temperature is halved?
11.2 L
What is the percent by mass of oxygen in CH3OH?
a. 50.0
b. 44.4
c. 32.0
d. 16.0
a. 50
Draw the Electron Dot Diagram (Lewis Dot Structure) for H2O
the hydrogens should be faces away
State the effect on the concentrations of H2O and CO2 when more H2 is added to the system
H2O increases
CO2 decreases
State what happens to the potential energy of the molecules in a solid sample of hexane at -95 degrees Celsius as heat is added until the hexane is completely melted
PE increase
A sample of 131I decay to 1.0 grams in 40 days. What was the mass of the original sample?
16 g
What is the percent by mass of oxygen in H2SO4? [Formular mass =98]
a. 16%
b. 33%
c. 65%
d. 98%
C. 65%
Explain in terms of charge distribution, why a molecule of carbon tetrachloride is a nonpolar molecule
The molecule is nonpolar because it has a symmetrical charge distribution. The electrons and distributed equally
State one stress, other than adding or removing NO2 or N2O4, that would increase the amount of the dark brown gas. (NO2 is a dark brown gas)
Increase temperature
State what interval 2 and 3 represents
2: The amount of activation energy required
3: The amount of energy gained
If 1/8th of an original sample of krypton-74 remains unchanged after 34.5 minutes, what is the half-life of krypton-74?
11.5 mins