You dissolve 0.47 g of potassium chloride (KCl) in 700 ml of water. What is the molarity of the solution?
(From the periodic table: 1 mol K = 39.10 g; 1 mol Cl = 35.453 g)
Enter the value rounded to three decimal places with no units
Will give BRAINLEst

0.009

Explanation:

Molarity, a measure of molar concentration of a substance is calculated thus;

Molarity = number of moles ÷ volume

According to the provided information, mass of KCl = 0.47g, volume of water = 700ml

Using mole = mass/molar mass

Molar Mass of KCl = 39.10 + 35.453

= 74.553g/mol

Mole = 0.47/74.55

Mole = 0.0063mol

Volume of water = 700ml = 700/1000 = 0.7L

Molarity = 0.006/0.7

Molarity = 0.00857

The value of molarity rounded to three decimal places (3 d.p) = 0.009

answer: - 3.) the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

solution: - as per the rules, oxidation number of oxygen in its compounds is -2. the sum of oxidation numbers of all the elements of a molecule or compound is zero.

also, the oxidation number in elemental form is zero.

in no, the oxidation number of o is -2 so the oxidation number of n is +2 so that the sum is zero.

similarly, the oxidation number of c in co is +2 and o is -2.

on product side the oxidation number of n is 0 as it is in the elemental form() .

oxidation number of c in carbon dioxide is +4 as there are two oxygen in it and we know that each oxygen is -2.

so, oxidation number of n is changing from +2 to 0 and the oxidation number of c is changing from +2 to +4.

since nitrogen is reduced and hence no is acting as an oxidizing agent. carbon is oxidized and so co is acting as a reducing agent.

so, the right choice is number 3.)the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.