Answer:

Explanation:
Molarity is found by dividing the moles of solute by liters of solution.

We are given grams of a compound and milliliters of solution, so we must make 2 conversions.
1. Gram to Moles
We must use the molar mass. First, use the Periodic Table to find the molar masses of the individual elements.
- C: 12.011 g/mol
- H: 1.008 g/mol
- O: 15.999 g/mol
Next, look at the formula and note the subscripts. This tells us the number of atoms in 1 molecule. We multiply the molar mass of each element by its subscript.
6(12.011)+12(1.008)+6(15.999)=180.156 g/mol
Use this number as a ratio.

Multiply by the given number of grams.

Flip the fraction and divide.


2. Milliliters to Liters
There are 1000 milliliters in 1 liter.

Multiply by 2500 mL.


3. Calculate Molarity
Finally, divide the moles by the liters.


The original measurement has 2 significant figures, so our answer must have the same. That is the hundredth place and the 3 tells us to leave the 7.

1 mole per liter is also equal to 1 M.

Molarity is defined as the number of moles of solute in 1 L of solution
molarity of solution to be prepared is 0.85 M
this means that there should be 0.85 mol of KBr in 1 L of solution
if 1 L contains - 0.85 mol
then 25.0 mL should contain - 0.85 mol / 1000 mL x 25.0 mL = 0.0213 mol
mass of KBr - 0.0213 mol x 119 g/mol = 2.53 g
mass of KBr that should be dissolved in 25.0 mL is 2.53 g
Answer:
1.5 hours or 90 minutes
Explanation:
Velocity = d/t
V = 64 mi / hour or 96 mi / 9 min OR 16 mi / 15 min
D = 96 miles
Velocity * Time = Distance
Time = Distance / Velocity
T = 96 mi / 64 mi / hour
96 / 64 = 1.5 mi per hour
T = 1.5 hours or 90 minutes