The melting of solid wax to form liquid wax and the evaporation of liquid wax to form wax vapor are physical changes. The burning of the wax vapor is a chemical change.
Answer: 1.24 × 10^25
Explanation:
× 
Using our knowledge in unit conversions, we know the mole units cancel each other out and all there's left is the atom unit. From here we can multiply the fractions and eventually we end with the number 124.0532 × 10^23
According to the scientific notation rules, the number to the left of the decimal cannot exceed 10 so we have to move the decimal to the left two spaces. With this change, we also have to change the exponent of the 10. Because we moved the decimal point two spaces to the left, that means we have 10^25.
Answer:
0.13 M
Explanation:
The reaction equation is;
NaOH(aq) + KHC8H4O4(aq) ------> KNaC8H4O4(aq) + H2O(l)
Molar mass of KHP = 204.22 g/mol
Amount of KHP= mass/ molar mass = 0.3365 g/204.22 g/mol = 1.65 × 10^-3 moles
n= CV
Where;
C= concentration
V= volume in dm^3
n= number of moles
C= n/V = 1.65 × 10^-3 moles × 1000/250 = 6.6 × 10^-3 M
If 1 mole of KHP reacts with 1 mole of NaOH
1.65 × 10^-3 moles of KHP will react with 1.65 × 10^-3 moles of NaOH
From
n= CV
We have that only 12.44 ml of NaOH reacted
C= n/V = 1.65 × 10^-3 moles × 1000/12.44
C= 0.13 M
At the equivalence point, the KHP solution turned light pink.
Answer:
a,d,e
Explanation:
its a,d, and e because clean air keeps us alive and other organisms need it to stay alive
