Determine the mass of gold that can be extracted if 25.0g of sodium cyanide is used.
4Au+8NaCN+O2--->4NaAu(CN)2+4NaOH
To determine the mass of gold that can be extracted, we need to use the given balanced chemical equation.
From the balanced equation:
4 moles of Au (gold) reacts with 8 moles of NaCN (sodium cyanide) to produce 4 moles of NaAu(CN)2 (sodium gold cyanide).
First, let's calculate the number of moles of NaCN used:
Given mass of NaCN = 25.0g
Molar mass of NaCN = 23.0g/mol + 12.0g/mol + 14.0g/mol = 49.0g/mol
Number of moles of NaCN = Mass / Molar mass
Number of moles of NaCN = 25.0g / 49.0g/mol ≈ 0.51 mol
According to the balanced equation, the ratio of NaCN to Au is 8:4. This means that for every 8 moles of NaCN used, 4 moles of Au are produced.
We can set up the following ratio to calculate the moles of Au:
8 moles NaCN: 4 moles Au = 0.51 mol NaCN: x moles Au
Cross-multiplying,
8 * x = 4 * 0.51
8x = 2.04
Dividing both sides by 8,
x = 2.04 / 8 ≈ 0.255 mol
The moles of Au produced is approximately 0.255 mol.
Finally, let's calculate the mass of Au:
Molar mass of Au = 196.97g/mol
Mass of Au = Moles of Au * Molar mass of Au
Mass of Au = 0.255 mol * 196.97g/mol ≈ 50.3g
Therefore, the mass of gold that can be extracted if 25.0g of sodium cyanide is used is approximately 50.3g.
To determine the mass of gold that can be extracted, we need to first calculate the stoichiometry of the reaction. The balanced equation you provided is:
4Au + 8NaCN + O2 ---> 4NaAu(CN)2 + 4NaOH
From the equation, we can see that 4 moles of gold (Au) react with 8 moles of sodium cyanide (NaCN) to produce 4 moles of sodium gold cyanide (NaAu(CN)2).
To find the mass of gold that can be extracted, we need to use the molar masses of gold (Au) and sodium cyanide (NaCN) and convert the given mass of sodium cyanide (25.0g) to moles.
The molar mass of gold (Au) is approximately 197.0 g/mol, and the molar mass of sodium cyanide (NaCN) is approximately 49.0 g/mol (22.9 g/mol for sodium + 14.0 g/mol for carbon + 14.0 g/mol for nitrogen).
Now, let's calculate the number of moles of sodium cyanide (NaCN) using the given mass:
Moles of NaCN = mass / molar mass
Moles of NaCN = 25.0 g / 49.0 g/mol
Moles of NaCN ≈ 0.510 moles
Using the stoichiometry of the balanced equation, we can determine the number of moles of gold (Au) by multiplying the moles of sodium cyanide (NaCN) by the stoichiometric ratio:
Moles of Au = (moles of NaCN) x (4 moles Au / 8 moles NaCN)
Moles of Au = 0.510 moles x (4/8)
Moles of Au = 0.255 moles
Finally, to find the mass of gold, we multiply the number of moles of gold by its molar mass:
Mass of Au = moles of Au x molar mass of Au
Mass of Au = 0.255 moles x 197.0 g/mol
Mass of Au ≈ 50.235 g
Therefore, approximately 50.235 grams of gold can be extracted if 25.0 grams of sodium cyanide is used.
Convert 25.00 g NaCN to moles. moles = grams/molar mass.
Using the coefficients in the balanced equation, convert moles NaCN to moles Au.
Now convert moles Au to grams. g = moles x molar mass.