Answer : The molecular weight of a substance is 157.3 g/mol
Explanation :
As we are given that 7 % by weight that means 7 grams of solute present in 100 grams of solution.
Mass of solute = 7 g
Mass of solution = 100 g
Mass of solvent = 100 - 7 = 93 g
Formula used :
where,
= change in freezing point
= temperature of pure water = 
= temperature of solution = 
= freezing point constant of water = 
m = molality
Now put all the given values in this formula, we get
Therefore, the molecular weight of a substance is 157.3 g/mol
However, Duncan has prepared ramen noodles so many times he does not need to measure the water carefully. If he happens to heat 0.850 ...
The grams of oxygen that are required to produce 1 mole of H₂O is 16 g ( answer B)
<u><em> calculation</em></u>
2 CH₄ + 2NH₃ +3 O₂ → 2HCN + 6H₂O
step 1: use the mole ratio to find moles of O₂
from equation above the mole ratio of O₂: H₂O is 3:6 therefore the moles of O₂ = 1 mole x3/6 =0.5 moles
step 2: find mass of O₂
mass= moles x molar mass
from periodic table the molar mass of O₂ = 16 x2= 32 g/mol
mass O₂ = 0.5 moles x 32 g/mol = 16 g (answer B)
Hydrocarbons. They usually burn. In fact, I can't think of one that does not.
A large volume of material will have a small amount of mass when the
material in question is gaseous or porous, and therefore has a lot of
space within it despite taking up a large amount of space overall.
