To find out how many moles there are in 2 kg of lithium bromide (LiBr), you need to follow these steps:
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Calculate the molar mass of LiBr:
- Lithium (Li) has an approximate atomic mass of 6.94 g/mol.
- Bromine (Br) has an approximate atomic mass of 79.9 g/mol.
Molar mass of LiBr = (6.94 g/mol) + (79.9 g/mol) = 86.84 g/mol.
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Convert the mass from kilograms to grams: \[ 2 , \text{kg} = 2000 , \text{g} \]
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Use the molar mass to find the number of moles: \[ \text{Number of moles} = \frac{\text{mass (g)}}{\text{molar mass (g/mol)}} \] \[ \text{Number of moles} = \frac{2000 , \text{g}}{86.84 , \text{g/mol}} \approx 23.05 , \text{moles} \]
So, there are approximately 23.05 moles in 2 kg of LiBr.