how many grams of copper hydroxide can b prepared from 2.7g of copper (II) nitrate and excess sodium hydroxide?
Write the equation and balance it.
Convert 2.7 g Cu(NO3)2 to moles. moles = grams/molar mass.
Using the coefficients in the balanced equation, convert moles copper(II) nitrate to moles copper(II) hydroxide.
Finally, convert moles copper(II) hydroxide to grams. grams = moles x molar mass.
To determine how many grams of copper hydroxide can be prepared from 2.7g of copper (II) nitrate and excess sodium hydroxide, we need to first calculate the molar mass of copper (II) nitrate and copper hydroxide.
1. Calculate the molar mass of copper (II) nitrate (Cu(NO3)2):
- Copper (Cu) has a molar mass of 63.55 g/mol.
- Nitrate (NO3) has a molar mass of 62.01 g/mol (14.01 g/mol for nitrogen and 3 * 16.00 g/mol for oxygen).
- The molar mass of copper (II) nitrate is:
Molar mass = (63.55 g/mol) + 2 * [(14.01 g/mol) + (3 * 16.00 g/mol)] = 63.55 g/mol + 2 * (14.01 g/mol + 48.00 g/mol) = 63.55 g/mol + 2 * 62.01 g/mol = 187.57 g/mol.
2. Copper (II) nitrate (Cu(NO3)2) contains one mole of copper ions (Cu2+) per mole of copper (II) nitrate. So, the molar mass of copper (II) nitrate is equal to the molar mass of copper ions.
3. Calculate the number of moles of copper (II) nitrate:
Moles = Mass / Molar mass = 2.7 g / 187.57 g/mol ≈ 0.014 moles.
4. Since copper (II) nitrate and sodium hydroxide react in a 1:2 molar ratio, we can use the mole ratio to find the number of moles of copper hydroxide formed.
5. The balanced chemical equation for the reaction between copper (II) nitrate and sodium hydroxide is:
Cu(NO3)2 + 2 NaOH → Cu(OH)2 + 2 NaNO3.
6. According to the balanced equation, 1 mole of copper (II) nitrate produces 1 mole of copper hydroxide (Cu(OH)2). So, the number of moles of copper hydroxide formed is equal to 0.014 moles.
7. Calculate the molar mass of copper hydroxide (Cu(OH)2):
- Copper (Cu) has a molar mass of 63.55 g/mol.
- Oxygen (O) has a molar mass of 16.00 g/mol.
- Hydrogen (H) has a molar mass of 1.01 g/mol.
- The molar mass of copper hydroxide is:
Molar mass = (63.55 g/mol) + 2 * [(1.01 g/mol) + (16.00 g/mol)] = 63.55 g/mol + 2 * (1.01 g/mol + 16.00 g/mol) = 63.55 g/mol + 2 * 17.01 g/mol = 63.55 g/mol + 2 * 34.02 g/mol = 63.55 g/mol + 68.04 g/mol = 131.59 g/mol.
8. Calculate the mass of copper hydroxide:
Mass = Moles × Molar mass = 0.014 moles × 131.59 g/mol ≈ 1.84 grams.
Therefore, approximately 1.84 grams of copper hydroxide can be prepared from 2.7 grams of copper (II) nitrate and excess sodium hydroxide.