Chemistry Mole and Reaction Quiz

How many molecules are present in 0.250 mol of CO₂?

• 6.02 x 10²² molecules

• 1.51 x 10²³ molecules

• 3.01 x 10²³ molecules

• 1.20 x 10²³ molecules

In a particular experiment, a 9.27g sample of Si reacts completely. The mass of O₂ consumed is _____ g. (mm Si = 28 g/mol ; mm O₂ = 32 g/mol)

2 Si + O₂ → SiO

• 0.993

• 2.65

• 3.09

• 5.30

Tags

NGSS.HS-PS1-7

How many moles of KBr are formed when 4 moles of BaBr₂ react completely?

BaBr₂ + K₂SO₄ → 2 KBr + BaSO₄

• 8 moles

• 6 moles

• 4 moles

• 2 moles

How many grams of water are produced when 2.50 mol oxygen reacts with hydrogen? (mm H₂O = 18 g/mol)

2 H₂ + O₂ →2 H₂O

• 18 g

• 45 g

• 90 g

• 160 g

Tags

NGSS.MS-PS1-5

Calculate the pressure in atm of 3.00 moles of a gas at 250°C that occupies 10.0 L.

• 6.14 atm

• 14.72 atm

• 408.5 atm

• 965.3 atm

In which flask would the pressure be the lowest?

• Flask 1

• Flask 2

• Flask 3

• Flask 4

The diagram shows a gas with an initial pressure of 3,060 mm Hg in a cylinder at a constant temperature. The gas expands inside the cylinder and pushes the piston up. What is the final pressure of the gas after the expansion?

• 544 mm Hg

• 784 mm Hg

• 2,898 mm Hg

• 3,230 mm Hg

What is the molarity of 600 mL of solution in which 3.0 moles of sodium bromide is dissolved?

• 0.005M

• 1.8 M

• 5 M

• 1,800 M

What volume of 1.0 M sodium phosphate, to the nearest tenth of a liter, must be used to make 4.0 L of 0.80 M sodium phosphate?

• 3.2 L

• 5.0 L

• 320 L

• 500 L

How many mL of a 15 M stock solution of HCl are required to make 300 mL of a 2.0 M solution?

• 10 mL

• 30 mL

• 40 mL

• 60 mL