Answer:
The molarity of ZnCl2 is 1.699 mol/ L.
Explanation:
Balance chemical equation:
Zn(s) + CuCl2(aq) → ZnCl2(aq) + Cu(s)
Given data:
mass of zinc = 30 g
total volume of solution = 270 mL
molarity of ZnCl2 = ?
Solution:
First of all we will calculate the moles of Zn.
molar mass of zinc = 65.38 g/mol
number of moles = mass / molar mass
number of moles = 30 g/ 65.38 g/mol
number of moles = 0.4588 mole
From the balance chemical equation we will compare the moles of Zn and ZnCl2
Zn : ZnCl2
1 : 1
0.4588 : 0.4588
The number of moles of ZnCl2 are 0.4588 mol.
Molarity of ZnCl2:
Total volume of solution is 270 mL. We will convert it into liter.
1 L = 1000 mL
270/1000 = 0.27 L
Molarity = moles of solute / volume of solution in liter
Molarity = 0.4588 mol / 0.27 L
Molarity = 1.699 mol/ L
Answer:
The mass of iron needed to react with the oxygen is 70 g.
Explanation:
The balanced chemical reaction between iron and oxygen is given as;
4Fe + 3O₂ ----------> 2Fe₂O₃
Molecular mass of 3O₂: 3(16 x 2) = 96 g
Molecular mass of 4Fe: 4(56) = 224 g
96 g of O₂ ---requires--------> 224 g of Fe
30 g of O₂ -------requires--------->? Fe
= (30 x 224) / 96
= 70 g
Therefore, the mass of iron needed to react with the oxygen is 70 g.
卂几丂山乇尺
Point "C" is correct and all the remaining are false.
Note, HomeAtomic and HeteroAtomic compounds are the types of compounds, but not homogenous and heterogenous.