ZnO(s) + 2HCl(aq) → ZnCl2 (s) + H2O(l)
Look at the moles:
1 + 2 → 1 + 1
How much ZnO do we need to make 50g of ZnCl2? Notice it is these numbers in () and should be 1:1
(1) + 2 → (1) + 1
So we need the same number of moles, but how many moles is 50g of ZnCl2? Zn weight is 65.38g, and Cl is 35.45g. So ZnCl2 is (65.38) + (2 X 35.45)=136.28g
50g/136.28g = 0.3669 moles
What is 0.3669 moles of ZnO now?
O weighs 16g/mol, so add 65.38 + 16 = 81.38
Multiply by 0.3669 moles and get how many grams we need.
B. Without a doubt,
(3.9-2.6)÷3.9
=33.3333...
≈33.33%
Answer:
C: Plants mostly need air, water and sunlight to grow
Explanation:
Answer:
B) we will convert the 10 g of NaCl into moles.
Explanation:
Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.
Formula:
Molarity = number of moles of solute / L of solution
we will convert the 10 g of NaCl into moles.
Number of moles of NaCl:
Number of moles = mass/molar mass
Number of moles = 10 g/ 58.44 gmol
Number of moles = 0.17 mol
1 Kg = 1 L
Molarity = 0.17 mol / 2 L
Molarity = 0.085 mol/L
Molarity = 0.085 M
