Chemistry Final Exam Review

WHMIS symbols represent various hazards in the lab. The WHMIS symbol that indicates a substance that is immediately toxic is (a)  

• Biohazardous Infectious Material

• Corrosive Material

• Poisonous and Infectious (Acute Tox

• Flammable Material

Answer explanation

The WHMIS symbol for substances that are immediately toxic is 'Poisonous and Infectious (Acute Tox)'. This symbol indicates a high risk of severe health effects upon exposure.

Which lab experiments below describe a situation where a chemical change has occurred? Check all that apply.

Tags

NGSS.MS-PS1-2

The following is what type of reaction?

PbCl₂ + 2AgNO₃ → Pb(NO₃)₂ + 2AgCl

• synthesis

• decomposition

• single replacement

• double replacement

What is the mass of 0.75 moles of (NH₄)₃PO₄?

• 101.75 g

• 121.75 g

• 111.75 g

• 131.75 g

2Na + 2H₂O → 2NaOH+ H₂
How many grams of hydrogen are produced if 120 g of Na are available?

• 5.2 g

• 2.6 g

• 690 g

• 45 g

Calculate the volume that a 0.323-mol sample of a gas will occupy at -8°C and a pressure of 0.900 atm.

• 7.18 L

• 7.81 L

• 4.63 L

• 4.36 L

A 250 mL sample of oxygen is collected over water at 25° C and 760.0 torr pressure. What is the pressure of the dry oxygen gas alone? (vapor pressure of water at 25° C = 23.8 torr)

• 783.8 torr

• 205.38 torr

• 1250 torr

• 736.2 torr

The half-life of strontium-90 is 25 years. How much strontium-90 will remain after 100 years if the initial amount is 4.0 g?

• 3.0g

• 0.25mg

• 0.3g

• 0.25g

Tags

NGSS.HS-PS1-8

Fe₂O₃ + C → Fe + 3CO₂. You react 28.00 grams of carbon. You find the actual yield to be 181.2 grams of CO₂. What is the percent yield of CO₂?

• 58.83%

• 308%

• 6435%

• 15.5

We know that combustion produces _____ because _____ turns cloudy when mixed with candle smoke.

• carbon dioxide; limewater

• carbon dioxide; cobalt chloride

• water; limewater

• water; cobalt chloride