Yes, because density is mass divided by volume. Density can't change unless a chemical change takes place, because density is how close together the molecules in a type of matter are. For example, the density of water is 1,000 kg/m³.
Answer:
CH4 + 2 O2 --> CO2 + 2 H2O
Explanation:
CH4 + 2 O2 --> CO2 + 2 H2O is the only reaction where an element (oxygen) undergoes a change in oxidation state. In this reaction oxygen changes disproportionately to O⁻². That is ...
O₂ → CO₂ + 4e⁻ ==> oxidation
<u>O₂ + 4e⁻ → H₂O ==> reduction </u>
2O₂ + 4e⁻ → CO₂ + H₂O + 4e⁻ ==> Net oxidation-reduction
=> 4e⁻ gained by one mole O₂ in formation of CO₂ = 4e⁻ lost by the other mole O₂ in forming H₂O.
Then...
Including CH₄ (whose elements do not undergo changes in oxidation states) requires doubling reaction to balance by mass thus giving ...
2CH₄ + 2O₂ + 8e⁻ → 2CO₂ + 2H₂O + 8e⁻
Cancelling 8 reduction electrons on left with 8 oxidation electrons on right gives...
2CH₄ + 2O₂ → 2CO₂ + 2H₂O
V = 550 mL = 0.550 L
V = 22.4 L/mol (STP)
M(CO₂)=44.01 g/mol
n(CO₂)=v/V
m(CO₂)=n(CO₂)M(CO₂)=vM(CO₂)/V
m(CO₂)=0.550*44.01/22.4=1.08 g
Answer:
1.51 x 10²⁴molecules
Explanation:
Given parameters:
Number of moles of NaCl = 2.5moles
Unknown:
Number of molecules = ?
Solution:
The number of molecules that can be found in a given mole is given as the Avogadro's constant;
1 mole of substance = 6.02 x 10²³ molecules
2.5 mole of NaCl = 2.5 x 6.02 x 10²³ molecules
= 1.51 x 10²⁴molecules
