Answer:
— Washing with soap and water is an effective way to destroy and dislodge many microbes
Explanation:
- Soap actually kill germs on our hands, it breaks them up and removes them
- .But soap molecules have two different ends to them.
- One end is attracted to water molecules – this is called hydrophilic
- – and the other end loves oil and fat molecules – this is called hydrophobic.
- Soap is able to bind to the oils on our hands, and then mix with the water to wash all the germs away.
Answer:
mass is 4.57 g
Explanation:
Ca(OH)₂ solution consists of Ca(OH)₂ solute molecules and solvent and we are asked to find the mass of Ca(OH)₂ in the solution
number of moles of Ca(OH)₂ is - 0.0787 mol
molar mass of Ca(OH)₂ is - 58.093 g/mol
we can use the following equation
number of moles = mass of Ca(OH)₂ / molar mass of Ca(OH)₂
rearranging the equation
mass of Ca(OH)₂ = number of moles x molar mass
mass = 0.0787 mol x 58.093 g/mol = 4.57 g
mass of Ca(OH)₂ is 4.57 g
Q1)
molarity is defined as the number of moles of solute in 1 L solution
the number of moles of LiNO₃ - 0.38 mol
volume of solution - 6.14 L
since molarity is number of moles in 1 L
number of moles in 6.14 L - 0.38 mol
therefore number of moles in 1 L - 0.38 mol / 6.14 L = 0.0619 mol/L
molarity of solution is 0.0619 M
Q2)
the mass of C₂H₆O in the solution is 72.8 g
molar mass of C₂H₆O is 46 g/mol
number of moles = mass present / molar mass of compound
the number of moles of C₂H₆O - 72.8 g / 46 g/mol
number of C₂H₆O moles - 1.58 mol
volume of solution - 2.34 L
number of moles in 2.34 L - 1.58 mol
therefore number of moles in 1 L - 1.58 mol / 2.34 L = 0.675 M
molarity of C₂H₆O is 0.675 M
Q3)
Mass of KI in solution - 12.87 x 10⁻³ g
molar mass - 166 g/mol
number of mole of KI = mass present / molar mass of KI
number of KI moles = 12.87 x 10⁻³ g / 166 g/mol = 0.0775 x 10⁻³ mol
volume of solution - 112.4 mL
number of moles of KI in 112.4 mL - 0.0775 x 10⁻³ mol
therefore number of moles in 1000 mL- 0.0775 x 10⁻³ mol / 112.4 mL x 1000 mL
molarity of KI - 6.90 x 10⁻⁴ M
The unit used to measure the volume of a solid is cubic centimeters.
