To make 44.0 grams of carbon dioxide, you must combine 12.0 g of carbon with 32.0 g of oxygen. if a chemist combines 120.0 g of carbon with 160.0 g of oxygen, how many grams of carbon dioxide will be made? if a substance is left over, indicate whether it is carbon or oxygen, and also determine how many grams of it are left over.

220 g of carbon dioxide will be made and 60 g of carbon will be left over

Explanation:

The ratio of the amount of carbon to that of oxygen to make carbon dioxode is given by

12/32 = 3/8

That is, we need 3 grams of carbon per 8 grams of oxygen to create 11 grams of carbon dioxide.

If we have 120 g of carbon we will need :

120 *(8/3) g = 320 g

of oxygen to produce 440 g of carbon dioxide.

However we only have 160 g of oxygen.

Now let us consider how many grams of carbon we need to be combined with 160 g of oxygen:

160 *(3/8)=60g

60 of carbon, will be used to create 220 g of carbon dioxide

Therefore, 220 g of carbon dioxide will be made and 60 g of carbon will be left over

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.

a mercury barometer is a device that uses the physical properties of mercury in a tube to measure barometric pressure. mercury barometers are used for : -

1. measurement of atmospheric pressure  

2. determining the altitude of a place

3. weather forecasting

4. calibration and checking of aneroid barometers

5. application in fluid mechanics

6. measurement of pressure in aircrafts

7. surface weather analysis

8. preparation of barographs

9. usage in physical sciences like physics, astronomy & chemistry

10. preparation of aircraft altimeters

characteristics of mercury barometer : -

1.used to define and measure atmospheric pressure.

2.on the average at sea level the column of mercury rises to a height of about 760 mm.

3.this quantity is equal to 1 atmosphere.

4.it is also known as standard atmospheric pressure.

5.a barometer in which the weight of a column of mercury in a glass tube with a sealed top is balanced against that of the atmosphere pressing on an exposed cistern of mercury at the base of the mercury column, the height of the column varying with atmospheric pressure.