Explanation:
Examples of chemical changes include, rusting, fire, and overcooking. Nuclear changes occur when the nuclei of atoms are rearranged to form new atoms. Examples of nuclear changes include atomic fission, nuclear fusion, and the energy of sun and stars.
A. A pure chemical substance consisting of one type of atom
An apple should be cut into 4 equal pieces, then put each slice in a separate container and label accordingly with letters A, B, C, and Control. Put water, ginger ale, and lemon juice into containers A, B, and C respectively but leave the Control untouched. Observe which of the slices in containers A, B, C will stay the same color after the one in control turns brown, if the slice maintains its color then the liquid added prevents an apple slice from browning. The variables are the liquids added and the control is the slice that did not have anything added to it.
Given :
10 gram sample of propane( C₂H₈ ).
To Find :
The number of moles of propane in given sample.
Solution :
Molecular mass of propane, M = (2 × 12) + ( 1 × 8 ) gram/mol
M = 32 gram/mol
We know, number of moles is given by :
Number of moles, n = m/M
n = 10/32 mol
n = 0.3125 mol
Therefore, number of moles in given sample is 0.3125 mol.