Acs

Which hydrocarbon is 84.1% carbon by mass?

• CH4

• C2H6

• C4H10

• C8H18

First-generation automobile airbags were inflated by the decomposition of sodium azide (M = 65.02):

2 NaN3(s) →2 Na(s) + 3 N2(g)

What mass of sodium azide would be required to inflate a 16.0 L airbag to a pressure of 1.20 atm at 17 ºC?

• 34.9g

• 52.4g

• 78.6g

• 157g

Lithium hydrogen carbonate, LiHCO3, decomposes when heated to form Li2O, CO2, and H2O. How many moles of H2O are formed when 0.50 mol LiHCO3 decomposes?

• 0.25mol

• 0.50mol

• 0.75mol

• 1.0mol

Tags

NGSS.HS-PS1-7

A portion of the phase diagram of uranium hexafluoride (UF6) is shown.

Which statements are correct?

I.UF6 sublimes at atmospheric pressure.

II. At 80 ºC and 1.5 atm, only UF6(g) is present at equilibrium

• I only

• II only

• Both I and II

• Neither I nor II

Tags

NGSS.HS-PS3-4

What is the order of the reaction with respect to A and B?

• 0 in A, 2 in B

• 1 in A, 1 in B

• 2 in A, 1 in B

• 1 in A, 2 in B

Tags

NGSS.HS-PS1-5

Choose the correct answer

• 25mL beaker

• 25mL graduated cylinder

• 25mL conical flask

• 25mL volumetric flask

Choose the correct answer

• Hold a test tube of the liquid under the nose and inhale the vapor

• Transfer a few drops of the liquid to the desk top and inhale the vapor from there

• Use a medicine dropper to collect a small quantity of the vapor and squirt this under the nose while inhaling

• Use a hand to fan some vapor from the test tube to the nose an inhale

Choose the correct answer

• 30.0mL

• 24.0mL

• 18.8mL

• 12.0mL

Choose the best answer

• Br

• N

• O

• S

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2