With chemistry !

1. a sample of gas takes up 45l. after being compressed down to a volume of 12l, the sample has a pressure of 5.7 atm. what was the original pressure?

2. a balloon takes up 32l of volume at 20˚c and a pressure of 212kpa. at what temperature will the balloon have a volume of 50l and a pressure of 300kpa?

3. at a temperature of 65˚c and a pressure of 1120mmhg, a large balloon takes up 25l. what will the volume become if the temperature is lowered to 5˚c?

4. at a temperature of 45˚c and a pressure of 250kpa, how many moles will fill a container that is 16l in volume?

5. a sample of gas in a rigid 20l container has a pressure of 2200mmhg and it is placed outside in the morning when the temperature is cold. throughout the day it warms up, and by the afternoon the temperature reaches 39˚c and the pressure inside the container is 2700mmhg. what was the temperature in the morning?

Thats the answer

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.

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.