Chemistry Homework Questions 8/4

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.)

H2 + Br2 -> 2 HBr

1 mol H2 / 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)

The “ell” is an old unit of measure equal to the length of one’s arm. (Hence the word “elbow.”) A stika is equal to 2 ells. How many square ells are in a square stika

4) What is the mass, in grams, of 3.7 cubic inches of magnesium?

5)

What is the correct name for Si3Cl8?

6)

How many electrons are in an Au+3 ion, assuming it’s gold-197?

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:

Ag2CO3 + CH2O → 2 Ag + 2 CO2 + H2

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.)

CHOOSE YOUR WRITER