Answer:
B
Explanation:
Recall the law of effusion:

Because 5 mol of oxygen was effused in 10 seconds, the rate is 0.5 mol/s.
Let the rate of oxygen be <em>r</em>₁ and the rate of hydrogen be <em>r</em>₂.
The molecular weight of oxygen gas is 32.00 g/mol and the molecular weight of hydrogen gas is 2.02 g/mol.
Substitute and solve for <em>r</em>₂:

Because there are 5 moles of hydrogen gas:

In conclusion, it will take about 2.5 seconds for the hydrogen gas to effuse.
Check: Because hydrogen gas is lighter than oxygen gas, we expect that hydrogen gas will effuse quicker than oxygen gas.
Answer is: a<span> fruit and oatmeal bar contains 142000 calories.
</span>A nutritional calorie<span>, or kilocalorie, is equal to 1000 calories.
</span>E = 142 kcal · 1000 cal/kcal.
E = 142 000 cal.
Calorie (cal)<span>, or small calorie, is the amount of energy needed to heat one gram of water by one degree Celsius.
</span><span>One small calorie is approximately 4.2 joules.
</span>A calorie is a unit of energy.
D. Electrons orbit in a fixed shell
Sulfur and chlorine. Explanation: A covalent bond is formed by two non-metals with similar electronegativities. As a consequence, they share one or more pairs of electrons between their nuclei
Answer:increasing the concentration of reactants
Explanation:
Collision is the phenomenon in which the reactant molecules come to nearest closness,as a result the reactants are converted into products.
Now the number of effective collision is directly proportional to the number of reactants added..