Where was the first permanent European settlement in what is now the United States?

Chromium(III) oxide reacts with hydrogen sulfide (H2S) gas to form chromium(III) sulfide and water: Cr2O3(s) + 3H2S(g) → Cr2S3(s

Tpy6a [65]

Answer:

(a) 0.779 mol Cr₂O₃

(b) 118 g Cr₂O₃

Explanation:

Step 1: Convert 156 g Cr₂S₃ to moles

Cr Molar Mass - 52.00 g/mol × 2 = 104.00 g/mol

S Molar Mass - 32.07 g/mol × 3 = 96.21 g/mol

156 g Cr₂S₃ ÷ 200.21 g/mol = 0.779182 mol Cr₂S₃

Step 2: Find conversion from Cr₂S₃ to Cr₂O₃

1 mol Cr₂S₃ equals 1 mol Cr₂O₃

Step 3: Use Dimensional Analysis

0.779182 mol Cr₂S₃ · $\frac{1 \hspace{2} mol \hspace{2} Cr_2O_3}{1 \hspace{2} mol \hspace{2} Cr_2S_3}$ = 0.779182 mol Cr₂O₃

0.779182 mol Cr₂O₃ ≈ 0.779 mol Cr₂O₃ (3 significant figures)

Step 4: Convert moles to grams

Cr Molar Mass - 52.00 g/mol × 2 = 104.00 g/mol

O Molar Mass - 16.00 g/mol × 3 = 48.00 g/mol

0.779182 mol Cr₂O₃ · 152.00 g/mol = 118.436 g Cr₂O₃

118.436 g Cr₂O₃ ≈ 118 g Cr₂O₃ (3 significant figures)

6 0

3 years ago

In an experiment, hydrochloric acid reacted with different volumes of sodium thiosulfate in water. A yellow precipitate was form

erastovalidia [21]

Answer:

The time taken for the cross mark to disappear decreases steadily down the column.

Explanation:

Now if we look at the data provided, we will discover that the volume of the HCl was held constant while the volume of the thiosulphate was increased steadily and the volume of water decreased steadily.

Recall that a system is more concentrated when it contains less volume of water and more volume of reactants. Hence as the volume of water in the system is being reduced, the concentration of reactants is increased.

It has been established that an increase in the concentration of reactants lead to an increase in the rate of reaction. The disappearance of the cross shows the completion of the reaction between HCl and thiosulphate. The faster or slower the cross disappears, the faster or slower the rate of reaction.

Since increase in concentration of reactants increases the rate of reaction, it is observed that as the volume of the thiosulphate increases (reactant concentration increases) the cross disappears faster (rate of reactant increases). Hence as the volume of thiosulphate increases, it takes a shorter time for the cross to disappear. This implies that the time column in the table (refer to the question) will decrease steadily as the volume of thiosulphate increases.

5 0

3 years ago

What host is used to make the flu vaccine and why can this host be a problem for some people?

valentinak56 [21]

Chicken eggs are used as host and this can be a problem for people with egg allergies!!

6 0

3 years ago

Express the ratio 1:<br><img src="https://tex.z-dn.net/?f=1%20%5Cfrac%7B1%20%7D%7B8%7D%20" id="TexFormula1" title="1 \frac{1 }{8

tester [92]

Explanation:

To out this fraction in its simplest form, you need to multiply the 8 by the 1 and then add the 1 in the numerator.

You end up getting