The velocity of the gas is inversely proportional to the square root of the molar mass of the gass. Heavier molecules tend to travel slow compared to light molecules. Among these, He has the lowest molar mass of 4 g/mol hence this element has the greatest velocity among all molecules given.
In the first 85.0 s of this reaction, the concentration of no dropped from 1.12 m to 0.520 m .
What is rate of a reaction?
The speed at which a chemical reaction takes place is the rate of the reaction. It is the concentration change per unit time of a reactant in a reaction.
Since the concentration of NO reduces to half its initial concentration in 85 seconds that is from 1.12m to 0.520m, it can be said that 85 seconds is the half life interval for the reaction, <u>Hence on average, </u><u>half reaction</u><u> is completed in the time interval of </u><u>85 seconds</u><u>.</u>
To learn more about rate of a reaction from the given link below,
brainly.com/question/12172706
#SPJ4
<span>Answer: 100 ml
</span>
<span>Explanation:
1) Convert 1.38 g of Fe₂S₃ into number of moles, n
</span>i) Formula: n = mass in grass / molar mass
<span>
ii) molar mass of </span><span>Fe₂S₃ =2 x 55.8 g/mol + 3 x 32.1 g/mol = 207.9 g/mol
</span>
iii) n = 1.38 g / 207.9 g/mol = 0.00664 moles of <span>Fe₂S₃
</span>
<span>2) Use the percent yield to calculate the theoretical amount:
</span>
<span>65% = 0.65 = actual yield/ theoretical yield =>
</span>theoretical yield = actual yield / 0.65 = 0.00664 moles / 0.65 = 0.010 mol <span>Fe₂S₃</span><span>
3) Chemical equation:
</span>
<span> 3 Na₂S(aq) + 2 FeCl₃(aq) → Fe₂S₃(s) + 6 NaCl(aq)
4) Stoichiometrical mole ratios:
</span>
<span>3 mol Na₂S : 2 mol FeCl₃ : 1 mol Fe₂S₃ : 6 mol NaCl
5) Proportionality:
</span>2moles FeCl₃ / 1 mol Fe₂S₃ = x / 0.010 mol Fe₂S₃
<span>
=> x = 0.020 mol FeCl₃
6) convert 0.020 mol to volume
</span>
<span>i) Molarity formula: M = n / V
</span>
<span>ii) V = n / M = 0.020 mol / 0.2 M = 0.1 liter = 100 ml
</span>
Answer:
18.75 milligrams of active ingredient is the recommended dose for a child weighing 36–47 lbs .
Explanation:
Recommended dose of an antihistamine for a child weighing 36–47 lbs = 1.50 tsp
1 table spoon of antihistamine has 12.5 mg per 5 mL of dose.
Amount of dose in 1 teaspoon = 
Volume of 1 tsp = 5 ml
Volume of 1.50 teaspoon = 
Amount of antihistamine in 7.50 mL :
18.75 milligrams of active ingredient is the recommended dose for a child weighing 36–47 lbs .
