I’m working on a Chemistry question and need guidance to help me study.
1) How many sig figs are in this mole ratio? (Write “999” for unlimited sig figs.) H_{2} + Br_{2} > 2 HBr 1 mol H_{2} / 2 moles HBr 2) If you convert 1.500°C to kelvin using this formula, how many sig figs are in the answer? (Write “999” for unlimited sig figs.) °C + 273 = K (Note that “273” has 3 sig figs.) 3)

4) What is the mass, in grams, of 3.7 cubic inches of magnesium?
5)
What is the correct name for Si_{3}Cl_{8}? 

6)
How many electrons are in an Au^{+3} ion, assuming it’s gold197? 

7)
How much heat must be removed to freeze 1.0 L of mercury, assuming it starts at the freezing point? Mercury’s enthalpy of fusion is 2.3 kJ/mol. 

8)
Write the electronic configuration of a Pu^{+3} ion (element #94,) using a noble gas in brackets. Format your answer like so: [Ne] 3s^2 3p^6 Make sure you list the orbitals in order of increasing energy. 
9)
What is the conjugate base of water? 

10)
You analyze a sample of a compound and find it is 85% mercury and 15% chlorine, by mass. Its molar mass is 472 g/mol. What is its molecular formula? 

11)
Consider the following reaction: Ag_{2}CO_{3} + CH_{2}O → 2 Ag + 2 CO_{2} + H_{2} How many grams of silver (I) carbonate do you need to use, if you want to get 5.0 grams of silver? 
12)Suppose you titrate 135 mL of a solution of KOH to neutrality using 26 mL of a known solution of 0.10 M sulfuric acid. What is the concentration of the KOH solution, in molar units?
13)
What is the pOH of a solution containing 0.00025 M H+? How many sig figs are in this conversion factor? (Write “999” for unlimited sig figs.) 
