<span>Ultra violet light is the catalyst that converts 7-dehydrocholesterol to provitamin D3. Ultra violet light can be obtained from the sun. The conversion happens when UVB light hits the skin (where 7-dehydrocholesterol naturally resides), gets absorbed, and us metabolized inside of the body.</span>
The theoretical yield of Li3N is 20.9 g .
Answer:
The answer is 0.0698 M
Explanation:
The concentration was prepared by a serial dilution method.
The formula for the preparation I M1V1 = M2V2
M1= the concentration of the stock solution = 0.171 M
V1= volume of the stock solution taken = 200 mL
M2 = the concentration produced
V2 = the volume of the solution produced = 940 mL
Substitute these values in the formula
0.171 × 200 = 490 × M2
34.2 = 490 × M2
Make M2 the subject of the formula
M2 = 34.2/490
M2 = 0.069795
M2 = 0.0698 M ( 3 s.f)
The concentration of the Chemist's working solution to 3 significant figures is 0.0698M
Answer:
B
Step-by-step explanation:
Equation B is balanced. It has four atoms of H and four of O on each side of the reaction.
A is <em>wrong</em>. It has two atoms of Cl on the left and only one on the right.
C is <em>wrong</em>. It has two atoms of O on the left and four on the right.
D is <em>wrong</em>. It has two atoms of Cl on the left and only one on the right.
