AP Chemistry

The Maxwell-Boltzmann distribution of molecular speeds in samples of two different gases at the same temperature is shown below. Which gas has the greater molar mass?

• Gas A

• Gas B

• both gasses have the same molar mass

• it cannot be determined unless the pressure of each sample is known

Tags

NGSS.HS-PS3-2

Which of the following is most likely to be a solid at room temperature?

• Na2S

• HF

• NH3

• N2

According to the balanced equation above, how many moles of CIO3 (aq) are needed to react completely with 20. ml of 2.0 mL of 2.0M KMnO4 solution?

• 0.0030 mol

• 0.0075 mol

• 0.013 mol

• 0.030 mol

Tags

NGSS.HS-PS1-7

2H2O2 (I) ---> 2H2O (I) + O2

the exothermic process represented above is best classified as a

• physical change because a new phrase appears in the products

• physical change because O2 that was dissolved comes out of the solution

• chemical change because entropy increases as the process proceeds

• chemical change because covalent bonds are broken and new covalent bonds are formed

A 0.10M aqueous solution of sodium sulfate, Na2SO4 is a better conductor of electricity then 0.10M aqueous solution of sodium chloride. Which of the following best explains this difference?

• Na2SO4 is more soluble than NaCl is

• Na2SO4 has a higher molar mass than NaCl has

• to prepare

• More moles of ions are present in a given volume of 0.10M Na2SO4 in the same volume of 0.10M NaCl

A 0.20 mol sample of MgCl(s) and a 0.10 mol sample of KCl (s) are dissolved in water and diluted to 500 ml. What is the concentration of CL- in the solution?

• 0.15 M

• 0.30 M

• 0.50 M

• 1.0 M

Tags

NGSS.HS-PS1-7

a 0.5 mol sample of he(g) and a 0.5 mol sample of Ne(g).....Which of the gases will escape faster through the pinhole and why?

• He(g) will escape faster because the He(g) atoms are moving at a higher average speed than the Ne(g) atoms

• Ne(g)

• Ne(g)

• both gases

a 1.0 L sample of a pure gas is found to have a lower pressure than predicted.....the best explaination for this observation is that the molecules of the gas.....

• have a combined volume that is too large

• have a lower molecular mass....

• are attracted to each other and do no exert as much force on the container walls as they would if they had no mutual attractions

• are attracted to the sides of the container....

CH3OH ---> CO + 2H2

what is the final pressure in the vessel after the reaction is complete and the contents of the vessel are returned to 600k?

• Pi/9

• Pi/3

• Pi

• 3Pi

The total pressure of the gas mixture is 5.00 atm/ The partial pressure of argon is

• 0.200 atm

• 0.500 atm

• 1.00 atm

• 2.00 atm