1) The answer is: 2 moles of oxygen molecules.
Balanced chemical reaction of methane combustion:
CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(g).
Coefficients with the lowest ratio indicate the relative amounts of substances in a reaction.
In fronf of oxygen molecule is coefficient 2.
2) The answer is: 4 moles of oxygen atoms.
In one molecule of oxygen there are two oxygen atoms, so in two molecules there are four oxygen atoms.
15. 1 were lost
16. 3 were gained
17. 2 were lost
18. 1 was gained
You can figure that out by looking at the number nest to the molecule with a plus or minus sign next to it
+ = gained
- = lost
A higher concentration of reactants leads to more collisions per unit time and leads to an increasing reaction rate. Changing the pressure of gaseous reactants is, in effect, changing their concentration. The increased number of collisions caused by a higher pressure generally increases the reaction rate.
Answer:
2.6 sec
Explanation:
The distance between the Earth and the moon = 240,000 miles
Also,
1 mile = 1609.34 m
So,
Distance between the Earth and the moon = 240,000 × 1609.34 m = 386241600 m
Speed of the light = 3 × 10⁸ m/s
Distance = Speed × Time.
So,
Time = Distance / Speed = 386241600 m / 3 × 10⁸ m/s = 1.3 sec
For back journey = 1.3 sec
<u>So, total time = 2.6 sec</u>
