Asolution is prepared by dissolving 20.1 g of mgcl2 with the addition of 157.0 ml of water (density of water is 1.00g/cm3). the density of the resulting solution was determined to be 1.089g/cm3. calculate the molar concentration of this solution: hint: make sure you understand the definition on molar concentration

1.3 M.

Explanation:

mass of the solution = mass of MgCl₂ + mass of water

mass of MgCl₂ = 20.1 g.

mass of water = d.V = (157.0 mL)(1.0 g/cm³) = 157.0 g.

∴ mass of the solution = mass of MgCl₂ + mass of water = 20.1 g + 157.0 g = 177.1 g.

V of the solution = (mass of the solution)/(density of the solution) = (177.1 g)/(1.089 g/cm³) = 162.62 mL = 0.163 L.

Molarity is the no. of moles of solute dissolved in a 1.0 L of the solution.

M = (no. of moles of MgCl₂) / (Volume of the solution (L)).

∴ M = (mass/molar mass)of MgCl₂ / (Volume of the solution (L)) = (20.1 g/95.211 g/mol) / (0.163 L) = 1.29 M ≅ 1.3 M.

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance

so she was walking and she stepped on warm jeffy , uh uh uhh dadye i just pooped my pants