Answer:
There will be a change of odor, color, temperature, and composition. These are all the changes assosiated with a chemical change.
<u>Answer:</u> The molality of 
solution is 4.013 m
<u>Explanation:</u>
Molality is defined as the amount of solute expressed in the number of moles present per kilogram of solvent. The units of molarity are mol/kg.
The formula used to calculate molarity:
.....(1)
Given values:
Given mass of = 20.0 g
Molar mass of = 62.3 g/mol
Mass of solvent = 80.0 g
Putting values in equation 1, we get:
Hence, the molality of solution is 4.013 m
Disappointed by A and the B
Answer:
Explanation:
3 )
18 grams of water contains 16 grams of oxygen .
Let the grams of oxygen needed be m .
yield is 75%
Only 75 % of m will make water .
.75 m will form water .
water formed by .75 m of oxygen = 18 / 16 x .75 m
Given that
18 / 16 x .75 m = 79
m = (16 x 79) / ( 18 x .75 )
= 93.63 grams .
So oxygen required is 93.63 grams .
4 )
One mole of water contains 0.5 moles of oxygen.
2 moles of oxygen will make 2 /,5 = 4 moles of water .
percent yield is 82 % ,
so water produced = .82 x 4 = 3.28 moles of water.
