Answer:
Mass = 4.6 g
Explanation:
Given data:
Number of molecules of sucrose = 8.1 ×10²¹ molecules
Mass of sucrose = ?
Solution:
First of all we will calculate the number of moles by using Avogadro number.
1 mole × 8.1 ×10²¹ molecules / 6.022×10²³ molecules
1.35 × 10⁻² mol
Mass of sucrose:
Mass = number of moles × molar mass
Molar mass = 342.3 g/mol
Mass = 1.35 × 10⁻² mol ×342.3 g/mol
Mass = 462.1 × 10⁻² g
Mass = 4.6 g
Answer:
The correct answer is 8.79 × 10⁻² M.
Explanation:
Based on the given information, the mass of NaI given is 4.11 grams. The molecular mass of NaI is 149.89 gram per mole. The moles of NaI can be determined by using the formula,
No. of moles of NaI = Weight of NaI/ Molecular mass
= 4.11 / 149.89
= 0.027420
The vol. of the solution given is 312 ml or 0.312 L
The molarity can be determined by using the formula,
Molarity = No. of moles/ Volume of the solution in L
= 0.027420/0.312
= 0.0879 M or 8.79 × 10⁻² M
I think its c, it makes sense to me to be c
C. 2Fe2O3 would be the correct answer!
Answer:
24.309 g/mol
Explanation:
To get the atomic mass, all we have to do is calculate with the masses of the three isotope, the real quantity present, taking account of the percent and then, do a sum of these three values. Like a pondered media.
For the first isotope:
23.99 * (78.99/100) = 18.95 g/mol
For the second isotope:
24.99 * (10/100) = 2.499 g/mol
For the last isotope:
25.98 * (11.01/100) = 2.86 g/mol
Now, let's sum all three together
AW = 18.95 + 2.499 + 2.86
AW = 24.309 g/mol