Answer:
Combining the two clear colorless liquids is a chemical change.
Explanation:
Because a different solid substance is formed. Tell students that a precipitate is an insoluble solid that forms when two solutions are combined and react chemically. Insoluble means that the solid will not dissolve.
Carbon dioxide is a gas having chemical formula 
, a gas which exhaled by humans and inhaled by plants. It is also emitted from the sources such as cement production and combustion of fossil fuels. It is also known as greenhouse gas associated with acidification of ocean.
Carbon dioxide with other gases acts like a blanket of Earth which absorbs infrared radiations emitted from the sun and thus, preventing the escaping of these rays into the outer space which results in the gradual heating of Earth's surface and atmosphere i.e. increase in temperature of Earth. This process is known as Global Warming.
Hence, carbon dioxide is responsible for the increase in warming of the atmosphere i.e. option (D).
Explanation:
the solid substance which left on the filter paper is called Residue
hope it helps ..............
To get the molecular formula we use the individual atomic masses of the atoms making the molecule. Hence, to get the factor by which the empirical formula is multiplied, we divide molar mass by the total of the mass of the atoms making the empirical formula.
(C2H7) the mass of one carbon atoms is 12 so two atoms add up to 24. The mass of one hydrogen atom is 1 a.m.u thus 7 atoms give a total of 7 a.m.u. The sum of the two types of atoms is 24+7= 31
Molar mass=62.18
62.18/31=2.0
Hence, (C2H7) 2=C4H14
