Question

Name a substance that the concentration can be adjusted
T/F The number of mols of solute determines the concentration
The number of particles/atoms/or molecules in 1mol of any substance is how much?
T/F One mol of copper is the same as one mol of Gold.

Answer 1

1. Often, a worker will need to change the concentration of a solution by changing the amount of solvent. Dilution is the addition of solvent, which decreases the concentration of the solute in the solution. Concentration is the removal of solvent, which increases the concentration of the solute in the solution.

2. The concentration of a substance is the quantity of solute present in a given quantity of solution. Concentrations are usually expressed in terms of molarity, defined as the number of moles of solute in 1 L of solution.

3. Chemists generally use the mole as the unit for the number of atoms or molecules of a material. One mole (abbreviated mol) is equal to 6.022×10^23 molecular entities (Avogadro's number), and each element has a different molar mass depending on the weight of 6.022×10^23 of its atoms (1 mole).

4. Because 1 mole is a fixed quantity of particles (6.022 × 1023 ), 1 mole of copper contains the same number of atoms as 1 mole of gold. Answer: Because each copper atom has less mass than each gold atom, 1 gram of copper contains more atoms than 1 gram of gold.