Question

Round your answer to the correct number of significant digits and show work.
1. How many grams of NaI would be used to produce a 2.0 M solution with a volume of 10.00 L?
2. What is the molarity of a 2.50 x 102 cm3 solution containing 450.0 g of C6H12O6 ?

3. How many moles of Sr(NO3)2 would be used in the preparation of 20.50 L of a 30.5 M solution?

Answer 1

20/10.00
149.89X20=2997.8 not sure

Answer 2

2) 450/250 =1.8

Answer 3

3)30.5=625.25/20.50 unsure what to do next on that one

Answer 4

@MALTMAN0004 2.0/10.00 149.89X2.0=30.g

Answer 5

okay i see it

Answer 6

If this "2.0/10.00 149.89X2.0=30.g" is for
"1. How many grams of NaI would be used to produce a 2.0 M solution with a volume of 10.00 L?"

then it's wrong.

first find the moles:

Molarity= n of solute/L of solution

2 M = n/10 L -> n =20 moles of NaI

then n=m/M, (i.e. moles=mass/Molar mass) -> m=n*M

m= 20*149.89 g/mol

so the first post was correct, but it was a fluke :P

Answer 7

he just didnt see the decimal. thank you though