Respuesta :
Answer:
2.5×10^-7mol/dm^3
Explanation:
Firstly convert the cm^3 to dm^3
200×1000=200000dm^3
Calculate the g/dm^3
2/200000=0.00001g/dm^3
To calculate mol/dm^3
Mol/dm^3=mass given\molar mass
=0.00001/40
=2.5×10^-7mol/dm^3
Answer:
0.25mol/dm^3
Explanation:
Let us calculate the number of mole in 2g of NaOH. This is illustrated below:
Molar Mass of NaOH = 23 + 16 + 1 = 40g/mol
Mass of NaOH given = 2g
Number of mole = Mass /Molar Mass
Number of mole of NaOH = 2/40 = 0.05mole
Volume = 200cm^3
1000cm^3 = 1dm^3
200cm^3 = 200/1000 = 0.2dm^3
Molarity = mole/Volume
Molarity = 0.05/0.2
Molarity = 0.25mol/dm^3