Answer:
A. 0.2395 w/w %
B. 2394ppm
Explanation:
A. To find concentrationin percent by mass of the solution we need to calculate mass of glycerol and mass of water. The formula is:
Mass glycerol / Total mass * 100
<em>Mass glycerol:</em>
The solution is 2.6x10⁻²moles / L. As there is 1L of solution there are 2.6x10⁻² moles of glycerol. In mass (Using molar mass glycerol: 92.09g/mol):
2.6x10⁻² moles of glycerol * (92.09g / mol) = 2.394g glycerol
<em>Mass of water:</em>
998.9mL and density = 0.9982g/mL:
998.9mL * (0.9982g/mL) = 997.1g of water.
That means percent by mass is:
% by mass: 2.394g / (997.1g + 2.394g) * 100 = 0.2395 w/w %
B. Parts per million are mg of glycerol per L of solution. As in 1L there are 2.394g. In mg:
2.394g * (1000mg / 1g) = 2394mg:
Parts per million: 2394mg / L = 2394ppm
C) a chemical change.
Chemical reactions will always convert a certain chemical(s) into one or more products.
They are not closely packed or arranged orderly.
Hope this helps!
<span>Density
is a value for mass, such as kg, divided by a value for volume, such as m3.
Density is a physical property of a substance that represents the mass of that
substance per unit volume. We calculate as follows:
Density = mass of gasoline/ volume of gasoline = (1</span>46.770 g -110.525 g ) / <span>50 ml = 0.7249 g/mL</span>
The answer is D you correct
