Which of these substances are compounds? How do you know?

A. Salt (NaCl)

B. Nitrogen (N)

C. Helium (He)

D. Water (H2O)

How many grams of solute are present in 645 mL of 0.410 M KBr?

A factor that changes in an experiment from manipulation of the independent variable is the what? a - hypothesis b-constant c-control d - dependent variable

Jeff wants to find the volume of a gas in a cylinder. He knows that at 28°C and a pressure of 1 atm, the volume of the gas was 6.0 L.

How many sulfur atoms are expected in the reactants of this chemical reaction? ? CaSO3 A. 0 B. 1 C. 2 D. 3

Can you give me an example of a chemical change?

How much ice at a temperature of - 17.5 ∘C must be dropped into the water so that the final temperature of the system will be 31.0 ∘C?

Why does a gas fill completely the vessel in which it is kept?

Individuals who work full time and those who work part-time enjoy basically the same number of paid leave benefits. True False

There is a large increase in ionization energy between the second and the third ionization energies of a metal. What kind of ion is the metal likely to form? Include the charge in your answer.

Which of the following are true statements about equilibrium systems? For the following reaction at equilibrium: CaCO3 (s) ⇌ CaO (s) + CO2 (g) adding more CaCO3 will shift the equilibrium to the right.