A gaseous mixture consists of 1.25 mol of helium, 0.36 mol of neon, and 1.58 mol of argon. 1st attempt What is the mole fraction of helium in the mixture?

19. Which of the following best describes the role of the spark from the spark plug in an automobile engine? (A) The spark decreases the energy of activation for the slow step. (B) The spark increases the concentration of the volatile reactant.

Organize the items listed into the proper sequence of events for gas exchange. a: O2 is transported to cells by circulatory system. b: O2 is drawn into the lungs during inhalation. c: Cells use O2 and generate CO2. d: CO2 is exhaled.

Which of the following is true about phase changes? Evaporation occurs when a solid changes into a gas. Condensation occurs when a gas changes into a liquid. Sublimation occurs when a solid changes to a liquid.

Plasma is often in stars, which are likely to contain?

Based on the solubility table given in table 1, which cation (or cations) will form soluble salts with all six anions (so42-, co32-, po43-, cl-, i-, no3-) ?

Using 3 O2 molecules and 5 H2 molecules, how many water molecules can be produced? Do you have any left over?

The specific heat of a certain type of cooking oil is 1.75 j / (g·°c). how much heat energy is needed to raise the temperature of 2.83 kg of this oil from 23 °c to 191 °c?

Which is true about the temperature of a gas? At a higher temperature, the particles have a higher average kinetic energy. At a higher temperature, the volume of the gas is smaller. At a lower temperature, there are more particles in the gas.

Convertible bonds are usually secured by a first or second mortgage. pay interest only in the event earnings are sufficient to cover the interest. may be exchanged for equity securities. have priority over other indebtedness.

What determines chemical properties and reactions? A. color of a substance B. size of the molecules C. atomic structure and bonds D. physical properties