June 2017 Chemistry Regents #16-20
Highlight to reveal answers and explanations
| |||
Questions | Answer | Links | Explanations |
16 The joule is a unit of (1) concentration (2) energy (3) pressure (4) volume | 2 | link | It on Table D |
17 Compared to a sample of helium at STP, the same sample of helium at a higher temperature and a lower pressure (1) condenses to a liquid (2) is more soluble in water (3) forms diatomic molecules (4) behaves more like an ideal gas | 4 | link | it is discussing ideal conditions of a gas high temperature and low pressure |
18 A sample of a gas is in a sealed, rigid container that maintains a constant volume. Which changes occur between the gas particles when the sample is heated? (1) The frequency of collisions increases, and the force of collisions decreases. (2) The frequency of collisions increases, and the force of collisions increases. (3) The frequency of collisions decreases, and the force of collisions decreases. (4) The frequency of collisions decreases, and the force of collisions increases. | 2 | link | gas particles travel faster and collide more often at higher temperatures. Particles travelling faster collide with more force |
| |||
19 At STP, which gaseous sample has the same number of molecules as 3.0 liters of N2(g)? (1) 6.0 L of F2 (g) (3) 3.0 L of H2(g) (2) 4.5 L of N2 (g) (4) 1.5 L of Cl2 (g) | 3 | link | equal volumes of a gas have the same number of molecules |
20. Distillation of crude oil from various parts of the world yields different percentages of hydrocarbons. Which statement explains these different percentages? (1) Each component in a mixture has a different solubility in water. (2) Hydrocarbons are organic compounds. (3) The carbons in hydrocarbons may be bonded in chains or rings. (4) The proportions of components in a mixture can vary. | 4 | link | mixtures can vary in composition, there maybe more octane in certain types of crude oil over others |
| |||