HELP 1. What is the pH at which a 10.0mM Os(NO3)2 will precipitate Os (OH)2 (s)? K3p of Os (OH)2 is 4.92 x 10^10 at 25.0C

7. Balance the following reaction under basic conditions: Al (s) + Cr2O72- (aq) -> Al3+ (aq) + Cr3+ (aq)

8. What is the ^o of the following balanced redox reaction (use the reduction potentials provided in Table 11.1
below)?

Fe3+ (aq) + Au (s) -> Fe (s) + Au3+ (aq)

9. What is G for the reaction below – calculate it from the ^o ?

Fe (s) + Au3+ (aq) -> Fe3+ (aq) + Au (s)

The wave shown on the electromagnetic spectrum disturb the medium it passes through a)different frequency. b)the same frequency .

Freezing and boiling are endothermic processes. this means that these processes absorb energy from their surroundings in order to occur. use this information and the data you collected in the phase change gizmo to describe what happens to the temperature of water when you boil it, then explain why this result occurs.

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.)