Basic Science

Question 1

For equations that ask “How many molecules are in XYZ ml of solution (SG= XYZ MW= XYZ)”

What equation do you use? (Not on the equation sheet)

Answer 1

molecules= (V x SG / MW) x avogadros number

Question 2

Equation for molecular weight

Answer 2

Molecular weight= grams/mole

Question 3

Equation for molar concentration:

Answer 3

Moles of solute / Liters of solution

Question 4

Question: what is the molar concentration of 50g NaCl dissolved in 500 ml water? (MW= 58.4)

Answer 4

1. Moles of NaCl:
   50g (1mole/58.4)= 0.856 moles
2. Molar concentration:
   0.856moles/0.500L= 1.7M

1.7M = answer

Question 5

Ideal gas law:

Answer 5

PV=nRT

R= 0.082