Dealing with a 0.150 M Co(NO3)2•6H2O. Determine the number of grams of Co(NO3)2•6H2O that you would need to weigh out in order to prepare 100.00 mL of the solution

4.365g

Explanation:

We'll begin by calculating the number of mole of Co(NO3)2•6H2O present in 100mL of 0.150 M Co(NO3)2•6H2O solution. This is illustrated below:

Molarity = 0.150M

Volume of solution = 100mL

Recall: 1000mL = 1L

Therefore, 100mL = 0.1L

Mole of solute (Co(NO3)2•6H2O) =?

Molarity is simply mole per unit litre of solution. It is represented mathematically as:

Molarity = mole /Volume

Mole = Molarity x Volume

Mole of Co(NO3)2•6H2O = 0.15x0.1

Mole of Co(NO3)2•6H2O = 0.015mol

Now, we need to convert 0.015mol to grams in order to obtain the desired result. This is illustrated below:

Mole of Co(NO3)2•6H2O = 0.015mol

Molar Mass of Co(NO3)2•6H2O = 59 + 2[14 + (16x3)] + 6[(2x1) + 16] = 59 + 2[14 + 48] + 6[2 + 16] = 59 + 2[62] + 6 [18] = 59 + 124 + 108 = 291g/mol

Mass of Co(NO3)2•6H2O =?

Mass = number of mole x molar Mass

Mass of Co(NO3)2•6H2O = 0.015 x 291

Mass of Co(NO3)2•6H2O = 4.365g

Therefore, 4.365g of Co(NO3)2•6H2O is needed to prepare 100mL of 0.150 M Co(NO3)2•6H2O solution.

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.