Find the mass of water (H2O) needed to react with 150 grams of potassium (K)
2K(s) + 2 H2O (g)-2KOH +H2(g)
How do I get the number of moles in H2O?
Find the mass of water (H2O) needed to react with 150 grams of potassium (K)
2K(s) + 2 H2O (g)-2KOH +H2(g)
How do I get the number of moles in H2O?
Desperate to understand this.
I got K= 150g./39.0983=3.84 mols of K.
Then would it be 3.84(2mols H2O/7.68)
How do I get the proper equation to figure out what 2 moles of H2O would be.
If you can walk me through this problem I will understand it and be able to continue with my work. Please help.
All you needed to do is/was follow my instructions. You found mols K.
See the second step in my earlier post.
http://www.jiskha.com/display.cgi?id=1414442701
Second step. Using the coefficients in the balanced equation, convert mols K to mols H2O. That's ? mols K x (2 mol H2O/2 mols K)
or mols H2O = ?mols K x 2/2 = the same as mols K
To find the number of moles of water (H2O), you need to use its molar mass.
The molar mass of a compound is the sum of the atomic masses of all the atoms in the compound. In the case of water (H2O), it consists of two hydrogen atoms (H) and one oxygen atom (O).
The atomic mass of hydrogen (H) is approximately 1 gram/mole, and the atomic mass of oxygen (O) is approximately 16 grams/mole. Adding these together, you get:
2(1g/mol) + 1(16g/mol) = 2g/mol + 16g/mol = 18g/mol
The molar mass of water (H2O) is therefore 18 grams/mole.
To calculate the number of moles of water (H2O) needed, divide the given mass (150 grams) by the molar mass:
Number of moles = Mass of substance / Molar mass
Number of moles of H2O = 150g / 18g/mol
By dividing 150 grams by 18 grams/mole, you will find that the number of moles of H2O needed is approximately 8.333 moles.