How many liters of chlorine gas (Cl2) will be needed to react with 42.00 g of potassium bromide (KBr)? 1 Cl2 + 2 KBr ---> 2 KCI + 1 Br2

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.)

Enzymes affect the reactions in living cells by changing the

Given the data below for the reaction, 2 a + 2 b + 4 c => d + e + 3 f, the reaction is fill in the [ ] order in a, fill in the [ ] order in b, fill in the [ ] order in c and fill in the [ ] order overall. (use the words "first, second, third, fourth" to fill each blank)experimentinitial conc of a, mol/l initial conc of b, mol/l initial conc of c, mol/l initial rate, mol/l.s1 0.1 0.1 0.2 2 x 10-32 0.2 0.3 0.2 6 x 10-33 0.3 0.1 0.2 2 x 10-34 0.4 0.3 0.4 1.2 x 10-2