It can change the phase of matter. The rest of the answers are chemical changes but increasing temperature indices a physical change which is only found in the first choice

4 0

3 years ago

Which of the following measurements is expressed to three significant figures?

matrenka [14]

The answer is C. 7.30 x 10^-7

8 0

3 years ago

What is the empirical formula? A compound is used to treat iron deficiency in people. It contains 36.76% iron, 21.11% sulfur, an

Mandarinka [93]

Answer: The empirical formula of the compound is $Fe_1S_1O_4$

Explanation:

Empirical formula is defined formula which is simplest integer ratio of number of atoms of different elements present in the compound.

Percentage of iron in a compound = 36.76 %

Percentage of sulfur in a compound = 21.11 %

Percentage of oxygen in a compound = 42.13 %

Consider in 100 g of the compound:

Mass of iron in 100 g of compound = 36.76 g

Mass of iron in 100 g of compound = 21.11 g

Mass of iron in 100 g of compound = 42.13 g

Now calculate the number of moles each element:

Moles of iron= $\frac{36.76 g}{55.84 g/mol}=0.658 mol$

Moles of sulfur= $\frac{21.11 g}{32.06 g/mol}=0.658 mol$

Moles of oxygen= $\frac{42.13 g}{16 g/mol}=2.633 mol$

Divide the moles of each element by the smallest number of moles to calculated the ratio of the elements to each other

For Iron element = $\frac{0.658 mol}{0.658 mol}=1$

For sulfur element = $\frac{0.658 mol}{0.658 mol}=1$

For oxygen element = $\frac{2.633 mol}{0.658 mol}=4.001\approx 4$

So, the empirical formula of the compound is $Fe_1S_1O_4$

4 0

3 years ago

Read 2 more answers

Can somebody help me please! Help would be much appreciated :))

vivado [14]

Answer:

The first picture shows how the two H athoms finds each other. The second one, how these H athoms start's to form a covalent bond describing it by Lewi's estructure. And the last one, shows how the two athoms of H formed an H2 molecula.

Explanation:

7 0

3 years ago