How many molecules of malic acid (C4H6O5), an acid found in apples and other fruits, are there in 1.25 g

5.61 * 10²¹ molecules

Explanation:

You have 1.25 g of malic acid, C4H.Os, an acid found in apples and other fruits. How many molecules of the acid do you have?

Solution:

A molecule is the group of two or more atoms held together by chemical bonds.

The number of molecules is calculated using the formula:

number of molecules in a substance = number of moles of substance * Avogadro constant

Avogadro constant = 6.02 * 10²³ mol⁻¹

number of moles = mass / molar mass

Given that mass = 1.25 g

molar mass of malic acid (C₄H₆O₅) = (12 * 4) + (1 * 6) + (16 * 5) = 48 + 6 + 80 = 134 g/mol

number of moles = mass / molar mass = 1.25 g / 134 g/mol = 0.0093 mol

Recall that: number of molecules in a substance = number of moles of substance * Avogadro constant

number of molecules in a substance = 0.0093 mol * 6.02 * 10²³ mol⁻¹ = 5.61 * 10²¹ molecules

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.