Answer:
The correct answer is Dust
Explanation
Dust is a dry dirt in powder form usually found on surfaces of items in a building, it comprises of very small particles of soil, sand and sometimes includes toxic substances, skin cells,bacteria, soil particles, particles of clothing material, tiny pieces of dead insects and pollen
Thus problem is providing us with the mass of iron (III) oxide as 12.4 g so the moles are required and found to be 0.0776 mol after the calculations:
<h3>Mole-mass relationships:</h3>
In chemistry, we use mole-mass relationships in order to calculate grams from moles and vice versa. In this case, since we are given the mass of iron (III) oxide as 12.4 g one can calculate the moles by firstly quantifying its molar mass:
Then, we prepare a conversion factor in order to cancel out the grams and thus, get moles:
Learn more about mole-mass relationships: brainly.com/question/18311376
You can solve this problem through dimensional analysis.
First, find the molar mass of NaHCO3.
Na = 22.99 g
H = 1.008 g
C = 12.01 g
O (3) = 16 (3) g
Now, add them all together, you end with with the molar mass of NaHCO3.
22.99 + 1.008 + 12.01 + 16(3) = 84.008 g NaHCO3. This number means that for every mole of NaHCO3, there is 84.008 g NaHCO3. In simpler terms, 1 mole NaHCO3 = 84.008 g NaHCO3.
After finding the molar mass of sodium bicarbonate, now you can use dimensional analysis to solve for the number of moles present in 200. g of sodium bicarbonate.
Cross out the repeating units which are g NaHCO3, and the remaining unit is mole NaHCO3
200. * 1 = 200
200/ 84.008 = 2.38
Notice how there are only 3 sig figs in the answer. This is because the given problem only gave three sig figs.
Your final answer is 2.38 mol NaHCO3.
Answer:
101.75 km/hr
Explanation:
average speed is the distance traveled ÷ time traveled
= 1221 ÷12 = 101.75 km/hr