BJU Chemistry Chapter 11 Review

How many moles are in 1.00 kg of NaCl?

• 580.400 mol

• 58.44 mol

• 17.1 mol

• 0.017 mol

Which formula indicates the elements that are present in a compound and gives the simplest whole-number ratio of the atoms?

• structural

• molecular

• mathematical

• empirical

What is the percent composition of DDT (C_14H_9Cl_5), formerly used as an insecticide in the United States?

• 57.44% C, 7.56% H, 35.01% Cl

• 47.44% C, 2.56% H, 50.01% Cl

• 68.49% C, 10.60% H, 20.91% Cl

• 37.45% C, 12.55% H, 50.00% Cl

A compound containing 80.00% C and 20.00% H has a molar mass of 30.00 g. What is the empirical formula of this compound?

• C_3H_8

• C_2H_6

• C_3H_2O

• CH_3

(True or False) A mole of H_2O contains the same number of atoms as a mole of CO_2.

• True

• False

Tags

NGSS.MS-PS1-1

In a chemical equation, the ________ represent the number of moles of each substance in a reaction.

• coefficients

• oxidation numbers

• electronegativity values

• ions

Tags

NGSS.HS-PS1-7

Stoichiometric conversions between substances in a reaction must be performed using moles because

• a conversion requires grams, and moles are measured in grams.

• the balanced equation is based on moles, not mass.

• a conversion requires a unitless dimension.

• individual atoms should be measured, not counted.

Tags

NGSS.HS-PS1-7

What mass of hydrogen (H₂) will react with 100.0 g of oxygen (O₂) to form water?

• 6.251 g

• 200.0 g

• 12.63 g

• 794.0 g

Tags

NGSS.HS-PS1-7

Acetylene gas (C₂H₂) is a flammable gas that can be prepared in the laboratory by reacting water with calcium carbide: CaC₂ + 2H₂O ⟶ C₂H₂ + Ca(OH)₂. How many moles of CaC₂ are needed to prepare 10.0 g C₂H₂?

• 0.15 mol

• 0.192 mol

• 0.384 mol

• 0.768 mol

Tags

NGSS.HS-PS1-7

Acetylene gas (C₂H₂) is a flammable gas that can be prepared in the laboratory by reacting water with calcium carbide according to the formula below. How many grams of C₂H₂ are formed from 0.385 mol CaC₂?