First we have to understand what a half life is. A half life is a measure of time when the amount of a certain object is 50% of the original amount. Hence the answer for this is letter A. The initial amount is 100. fifty percent of 100 is 50 and that happens after 15 hours. Hence, 15 hours is the half life period.
Answer:
5.66 %.
Explanation:
<em>mass percent is the ratio of the mass of the solute to the mass of the solution multiplied by 100.</em>
<em />
<em>mass % = (mass of solute/mass of solution) x 100.</em>
<em></em>
mass of potassium nitrite = 30.0 g,
mass of the solution = mass of water + mass of potassium nitrite = 500.0 g + 30.0 g = 530.0 g.
<em>∴ mass % = (mass of solute/mass of solution) x 100</em> = (30.0 g/530.0 g) x 100 = <em>5.66 %.</em>
Answer: V1 = 45.6 ml
Explanation:
This is a dilution process whereby the concentration of phosphate in the solution is being reduced from 4.5m to 2m. Meanwhile. In a concentration process, the concentration of the phosphate solution will be increased. It can be achieved by removing solvents.
The dilution equation will be used. The equation is as follows:
M1V1 = M2V2 where
V1 = Initial volume of phosphate solution.
M1 = Initial concentration of phosphate solution.
V2 =Final volume of phosphate solution.
M2 = Final concentration of phosphate solution .
From the information given,
M1 = 4.5
V1 = ?
M2 = 2.0
V2 = 80
4.5 × V1 = 2×80
4.5V1 = 160
V1 = 160/4.5
= 35.6 ml
Sometimes it can be true, but if you think of it another way: the warmer the water is, the quicker the substance dissolves in that...
Meaning you have to give heat to the system (ex. tea) in order to get e.g. the sugar dissolved :) However, in extreme cases heat can also be released!
