Which is an example of a chemical change?

a. frying an egg

b. boiling water

c. melting butter

d. chopping onions

What is the mole fraction, x, of solute and the molality for an aqueous solution that is 16.0 % NaOH by mass

What are the independent and dependent variables in each of the experiments?

What is the correct formula for nickel (ll) perchlorate? (a) NiClO4 b) Ni2ClO4 c) Ni (ClO4) 2 (d) NiClO3 e) Ni (ClO3) 2

Why is there no overall charge on an aluminium atom?

Assume that a milliliter of water contains 20 drops. How long, in hours, will it take you to count the number of drops of water in 1.0 gal of water at a counting rate of 10 drops/s?!

Which equations represent precipitation reactions? More than one can be chosen. A. Na2S + FeBr2 → 2NaBr + FeS B. MgSO4 + CaCl2 → MgCl2 + CaSO4 C. LiOH + NH4I → LiI + NH4OH D. 2NaCl + K2S → Na2S + 2KCl E. AgNO3 + NaCl → AgCl + NaNO3

The amount of massin a given volume of air is

What is the molarity of a solution that contains 612 grams of CaCl2 in 3.04 liters of solution? 1.81 M 201 M 5.52 M

What is the empirical formula for naphthalene

Explain why a piece of aluminum or magnesium can be used to remove tarnish, which is mostly silver sulfide, on silverware.