To make a 2 m solution of calcium chloride (cacl2), you would place how many grams of cacl2 into a container and then add how much pure water? [mass of a ca atom = 40; mass of a cl atom = 35; mass of an o atom = 16; mass of an h atom = 1] a) 220 grams of cacl2 then add water to make a total volume of 1 liter b) 128 grams of cacl2 then add water to make a total volume of 1 liter c) 150 grams of cacl2 then add water to make a total volume of 1 liter. d) 110 grams of cacl2 then add water to make a total volume of 1 liter e) none of the above is correct

For a volume of 1 liter, we have a total mass of 220 grams of CaCl2 ( Option A)

Explanation:

Step 1: Given data

The concentration of the solution we want to make is 2M

2M = 2 moles/ L So the volume = 1L

The molar mass of CaCl2 is = 40 + 2*35 = 110g/mole

Step 2: Calculate number of moles

If we consider the volume = 1 L then for a concentration of 2M, this means the number of moles is 2

Step 3:  Calculate mass

The molar mass of CaCl2 = 110 g/mole

This means 110 grams per 1 mole

for 2 moles the mass is 220 grams

This means that for a volume of 1 liter, we have a total mass of 220 grams of CaCl2

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

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~ trueboss72