A17.0-g sample of hf is dissolved in water to give 2.0 x 10 2 ml of solution. the concentration of the solution is:

The concentration of the HF solution: M = 4.25 M

Explanation:

Molarity, denoted by M, is the molar concentration of a given solution. It is the ratio of number of moles of solute and the total volume of the solution in L.

Molarity of a solution is given by,

and,  

Given: Total volume of solution: V = 2 × 10² mL = 2 × 10² × 10⁻³ L = 0.2 L    (∵ 1 mL = 10⁻³ L)

Given mass of solute (HF): w = 17 g, Molar mass of solute (HF): m = 20 g/mol

Molarity of HF solution: M = ?

So the number of moles of solute (HF):

Therefore, the Molarity of the HF solution:

Therefore, the concentration of the HF solution: M = 4.25 M

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.

in cartography, a contour line (often just called a "contour") joins points of equal elevation (height) above a given level, such as mean sea level. a contour map is a map illustrated with contour lines, for example a topographic map, which thus shows valleys and hills, and the steepness or gentleness of slopes.

explanation: