Answer:
25.89 × 10²³ molecules
Explanation:
Given data:
Mass of CoCl₂ = 560 g
Number of molecules present = ?
Solution:
Number of moles of CoCl₂:
Number of moles = mass/molar mass
Number of moles = 560 g/ 129.84 g/mol
Number of moles = 4.3 mol
Avogadro number:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance. The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ molecules
4.3 mol × 6.022 × 10²³ molecules /1 mol
25.89 × 10²³ molecules
I just took a test with this question and got the answer wrong for saying ethane. The correct answer is propane.
Answer:
Explanation:
1) Molarity of the solution is (0.50/0.75)x1 = 0.66666 Mol/L
2) Molar mass of NaCl is 23+35 = 58g
Molarity = (0.5/58)/0.075 = 0.115 Mol/L
3) Molar mass of 
= 7x2 + 32 + 16x2 = 78g
Molarity = (734/78)/0.875 = 10.754 Mol/L
5) Molar mass of
= 207.2 + ((12x2) + (1x3) + (16x2))x4
= 207.2 + (24+3+32)x4 = 443.2g
Molarity = (0.0672/443.2)/0.1335 = 0.001135 Mol/L
6) Both are the same.
Solution 1 Molarity = 1.0/1.0 = 1 Mol/L
Solution 2 Molarity = 1.0/1.0 = 1 Mol/L
Molarities of the solutions are the same.
Answer: 0.123 M
Explanation:
According to the neutralization law:
where,
= molarity of 
solution = ?
= volume of solution = 15.00 ml
= molarity of 
solution = 0.100 M
= volume of solution = 18.44 ml
= valency of = 1
= valency of = 1
Therefore, the concentration of the unknown HBr solution is 0.123 M
