Nothing.
Ignoring evaporation, the mass stays the same as ice turns to water. It's a physical change, not a chemical.
The density of the unknown solid is 20 g/ml. This is calculated by dividing the mass (40g) by the volume (2ml).
40g
The water is 38g and the salt 2g, so long as there is nothing else in the water
Grams can't be converted to cc. Grams measure mass, while cc measure volume.
6g
the mass does not change only the shape
2g per cm3
The density of the object is 2 g/cm3. This is calculated by dividing the mass (40g) by the volume (20cm3).
A standard sugar cube typically weighs about 4 grams. Therefore, to find out how many sugar cubes are in 40 grams, you would divide 40 by 4, resulting in 10 sugar cubes.
The density of the unknown solid is 20 g/ml. This is calculated by dividing the mass (40g) by the volume (2ml).
Since the gram atomic mass of calcium is 40.08 and calcium does not form polyatomic molecules, the number of moles in 40g of calcium is 1.0, to the justified number of significant digits.
40g
The water is 38g and the salt 2g, so long as there is nothing else in the water
The mass of the sugar water would still be 40g. When a solute, like sugar, is dissolved in a solvent, like water, the mass of the solution remains the same as the individual components do not change their mass through dissolution.
Density = 2 g/cm3
The mass of an anchor is 40 kg. 40 g would be too light for an anchor.
To find the mass of hydrogen needed to react with 40g of copper oxide (CuO), first calculate the molar mass of CuO. Then, use stoichiometry to determine the moles of CuO present in 40g. From the balanced chemical equation CuO + H2 -> Cu + H2O, you can determine the mole ratio between CuO and H2. Finally, use the molar mass of hydrogen to calculate the mass of hydrogen needed to react.