In this question, you are given the average cofactor mass per cell (77.91pg) and the total cells count(10^5 cells). You are asked how much cofactor that will be found from those cells(microgram= 10^6 picogram). Then the calculation would be:
Cofactor mass= cofactor per cell * cell count= 77.91pg/cell * 10^5 cells= 7.791 x 10^6pg
Then convert the picogram(pg) into microgram: 7.791x 10^6pg/ (10^6pg/microgram)= 7.791 microgram
1)we need a balanced equation: CuSO₄ + Zn ---> ZnSO₄ + Cu
2) we need to convert the grams of CuSO₄ to moles using the molar mass.
molar mass CuSO₄= 63.5 + 32.0 + (4 x 16.0)= 160 g/mol

3) convert moles of CuSO₄ to moles of Cu

4) convert moles of Cu to grams using it's molar mass.
molar mass Cu= 63.5 g/mol

I did it step-by-step as the explanation but you can do all of this in one step.
Answer:- 1840 g.
Solution:- We have been given with 3.35 moles of
and asked to calculate it's mass.
To convert the moles to grams we multiply the moles by the molar mass of the compound. Molar mass of the compound is the sum of atomic masses of all the atoms present in it.
molar mass of
= atomic mass of Hg + 2(atomic mass of I) + 6(atomic mass of O)
= 200.59+2(126.90)+6(16.00)
= 200.59+253.80+96.00
= 550.39 gram per mol
Let's multiply the given moles by the molar mass:

= 1843.8 g
Since, there are three sig figs in the given moles of compound, we need to round the calculated my to three sig figs also. So, on rounding off to three sig figs the mass becomes 1840 g.
The answer is 3.39 mol.
<span>Avogadro's number is the number of molecules in 1 mol of substance.
</span><span>6.02 × 10²³ molecules per 1 mol.
</span>2.04 × 10²⁴<span> molecules per x.
</span>6.02 × 10²³ molecules : 1 mol = 2.04 × 10²⁴ molecules : x
x = 2.04 × 10²⁴ molecules * 1 mol : 6.02 × 10²³ molecules
x = 2.04/ 6.02 × 10²⁴⁻²³ mol
x = 0.339 × 10 mol
<span>x = 3.39 mol
</span>
Hello!
Calvin told Marie that they could continue to add solute until the reached 40 grams because the solution was still unsaturated.
Unsaturated solutions are those in which the solvent (in this case water) can still dissolve more solute (in this case KNO₃) at the given pressure and temperature. This can be seen visually when adding more solute doesn't result in the presence of grains of solids that settle in the bottom of the flask. That happens because the rate of dissolving is higher than the rate of crystallization.
Have a nice day!