Water (H2O) and hydrogen fluoride (HF) are both polar molecules. Which of the following statements are true about the attractions between water and hydrogen fluoride when they are mixed together? Choose the two statements that apply. (Hint: In HF, the F atom attracts the shared electron more than the H atom.) A. The H in HF and the H in H2O attract each other.
B. The H in HF and the O in H2O attract each other.
C. The F in HF and the H in H2O attract each other.
D. The F in HF and the O in H2O attract each other.

Which is a chemical property of iron? a. it forms iron oxide (rust) when exposed to moisture and air. b. it is a gray–black metal that is hard to the touch. c. it has a melting point of 2795°f (1536°c). d. it is a good conductor of heat

Calculate the number of molecules present in 0.750 mol of mgo.

Modern pennies are composed of zinc coated with copper. a student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coaling (to expose the underlying zinc). the student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the hcl (the copper remains undissolved): zn(s) + 2 hcl(aq) → h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 °c. the collected gas occupies a volume of 0.899 l at a total pressure of 79 j mmhg. calculate the percent zinc (by mass) in the penny. (assume that all the zn in the penny dissolves.)