seawater contains approximately 3.5% NaCl by mass and has a density of 1.02g/mL. What volume of seawater contains 1.0 g of sodium? Please Help!
3.5% NaCl w/w means 3.5 g NaCl/100 g soln.
Since the density is 1.02 g/mL, you know that 100 g must have a volume of
v = m/d = 100/1.02 = about 98 but you need to confirm that.
Then 98 x (1/3.5) = ?? mL for 1 gram.
To find the volume of seawater that contains 1.0 g of sodium, we need to determine the mass of sodium in seawater, and then use the density of seawater to convert that mass into volume.
1. First, we need to calculate the mass of sodium in seawater. Given that seawater contains 3.5% NaCl by mass, we can assume that all the sodium in seawater comes from salt (NaCl). Since the molar mass of NaCl is approximately 58.44 g/mol, we can calculate the mass of sodium using the following steps:
- Calculate the molar mass of sodium (Na) by multiplying the atomic mass of sodium (22.99 g/mol) by 1, as there is one sodium atom in one molecule of NaCl.
Molar mass of Na = 22.99 g/mol * 1 = 22.99 g/mol
- Calculate the mass of NaCl in 100g of seawater:
Mass of NaCl = 3.5g/100g * 100g = 3.5 g
- Calculate the number of moles of NaCl:
Moles of NaCl = mass of NaCl / molar mass of NaCl = 3.5g / 58.44 g/mol
- Convert the moles of NaCl to moles of sodium (Na) by multiplying by the ratio of moles of Na to moles of NaCl, which is 1:1 as one mole of NaCl contains one mole of Na:
Moles of Na = Moles of NaCl * (1 mole Na / 1 mole NaCl)
- Finally, compute the mass of sodium (Na) in seawater:
Mass of sodium = Moles of Na * molar mass of Na
2. Once we know the mass of sodium in seawater, we can use the density of seawater to convert this mass into volume. Given that the density of seawater is 1.02 g/mL:
- Calculate the volume of seawater containing 1.0 g of sodium:
Volume = Mass of sodium / Density of seawater
Substituting the calculated values, we can find the volume of seawater that contains 1.0 g of sodium.