Answer:

Explanation:
<u><em>Given :</em></u>
Mass in grams = m = 42 g
Molar Mass = M = 12
<u><em>Required:</em></u>
No. of moles = n = ?
<u><em>Formula :</em></u>
m = m / M
<u><em>Solution:</em></u>
n = 42 / 12
n = 3.5 moles
Answer:
the answer is c
Explanation:
a chemical change mean it changes it for ever and a physical change mean it can be changed back and evaporation means it turns solid water in to gas hope this helps
Number of moles= mass/ molar mass
Or n=m/MM
n = number of moles
m = mass
MM = molar mass
1) n CuO = 2.4g / 79.54g/mol = 0.03 mol CuO
2) n Cu(NO3)2.xH2O = 7.26 g / 205.6 = 0.035 moles of Cu(NO3)2.xH2O
3) 205.6 g
Cu = 63.5 g
N = 14g
O =16g
H= 1 g
63.5+ (14+(16*3))*2+1*2+16 =205.6 g
4) yes is 188g
5) I don’t know, I assume was 1
I believe the appropriate pair is O and S, Periodic table represents arrangements of elements ordered by their atomic number,physical and chemical properties. Both sulfur and oxygen are in the same group of the periodic table (group 6), they have a valency of 2, This means they have a greater similarity in chemical and physical properties.