A chemical reaction yields 3 moles of lithium hydroxide (LiOH). How many grams of lithium hydroxide are present?
24 g
48 g
72 g
When ethane (C2H6) burns, it produces carbon dioxide and water:
2C2H6 (g) + 7O2 (g) 4CO2 (g) + 6H2O (l)
How many moles of water will be produced when 16 moles of ethane are burned?
32 moles
48 moles
64 moles
g = mols x molar mass
Use the coefficients in the balanced equation to convert mols ethane to mols H2O
16 mol ethane x (6 mols H2O/2 mols ethane) = ?
To calculate the grams of lithium hydroxide (LiOH) produced, we need to know the molar mass of lithium hydroxide.
The molar mass of LiOH can be calculated as follows:
Molar mass of Li = 6.94 g/mol
Molar mass of O = 16.00 g/mol
Molar mass of H = 1.01 g/mol
So, the molar mass of LiOH = (6.94 g/mol) + (1.01 g/mol) + (16.00 g/mol) = 23.95 g/mol
Now, we can calculate the grams of LiOH produced:
3 moles * 23.95 g/mol = 71.85 g ≈ 72 g
Therefore, the correct answer is 72 g.
For the second question, we need to use the balanced equation for the combustion reaction:
2C2H6 (g) + 7O2 (g) → 4CO2 (g) + 6H2O (l)
Based on the stoichiometry of the balanced equation, we can see that for every 2 moles of C2H6 burned, 6 moles of H2O are produced.
So, if 16 moles of C2H6 are burned, we can calculate the moles of H2O produced as follows:
16 moles C2H6 * (6 moles H2O / 2 moles C2H6) = 48 moles
Therefore, 48 moles of water will be produced when 16 moles of ethane are burned.
So, the correct answer is 48 moles.
To find the number of moles of lithium hydroxide (LiOH) present, we need to use the molar mass of LiOH and the given number of moles.
The molar mass of LiOH can be calculated by adding the atomic masses of lithium (Li), oxygen (O), and hydrogen (H).
- The atomic mass of lithium (Li) is approximately 6.94 g/mol.
- The atomic mass of oxygen (O) is approximately 16.00 g/mol.
- The atomic mass of hydrogen (H) is approximately 1.01 g/mol.
So the molar mass of LiOH is approximately 6.94 + 16.00 + 1.01 = 23.95 g/mol.
Now, we can calculate the mass of LiOH using the given number of moles.
3 moles of LiOH * 23.95 g/mol = 71.85 g
Therefore, there are approximately 72 grams of lithium hydroxide (LiOH) present.
For the second question, we can use the balanced chemical equation to determine the moles of water (H2O) produced when ethane (C2H6) is burned.
According to the balanced equation:
2C2H6 (g) + 7O2 (g) --> 4CO2 (g) + 6H2O (l)
We see that for every 2 moles of C2H6, 6 moles of H2O are produced.
Therefore, if 16 moles of C2H6 are burned:
16 moles of C2H6 * (6 moles of H2O / 2 moles of C2H6) = 48 moles of H2O
Thus, 48 moles of water (H2O) will be produced when 16 moles of ethane (C2H6) are burned.