Answer:
Physical change is a temporary change. A chemical change is a permanent change.
Explanation:
A Physical change affects only physical properties i.e. shape, size, etc. Chemical change both physical and chemical properties of the substance including its composition.
Answer:
The original number of oxygen atoms was about 80 times larger than Avogadro's number. Since each sulfuric acid molecule contains 4 oxygen atoms, there are about 20 moles of sulfuric acid molecules.
Answer:
THE INITIAL VOLUME OF THE STOCK SOLUTION IS 0.0392 L OR 39.2 mL
Explanation:
To calculate the volume of a solution before dilution, we make use of the dilution formula;
C1 V1 = C2 V2
C1 = the concentration of the stock solution = 15 M
V 1 = the volume of stock solution = ?
C2 = concentartion of final solution = 2.35 M
V2 = volume of final solution = 250 mL = 250/ 1000 = 0.25 L
Rearranging the formula, we obtain;
V1 = C2V2 / C1
V 1 = 2.35 * 0.25 / 15
V1 = 0.5875 / 15
V1 = 0.0392 L
the initial volume of the stock solution is 0.0392 L or 39.2 mL
