Which of the statements describes a chemical property?

Stolb23 [73]

Answer:

D. These elements have properties of both metals and nonmetals.

Explanation:

It can be concluded that the elements have properties of both metals and non-metals.

The elements that borders the ones described are both metals and non-metals. Most of these elements can be classified as metalloids.

On the periodic table, the elements around this region have properties of both metals and non-metals at certain temperature and pressure conditions.

3 0

3 years ago

Read 2 more answers

What is the empirical formula for a compound that contains 10.89% magnesium 31.77% chloride and 57.34% oxygen

Blizzard [7]

Answer: $Mg_{1}Cl_{2}O_{8}$

Explanation:

If percentage are given then we are taking total mass is 100 grams.So, the mass of each element is equal to the percentage given.

Mass of Mg = 10.89 g

Mass of Cl = 31.77 g

Mass of O = 57.34 g

Step 1 : convert given masses into moles.

Moles of Mg= $\frac {\text{ given mass of Mg}}{\text{ molar mass of Mg}}= \frac {10.89g}{24g/mole}=0.45moles$

Moles of Cl = $\frac {\text{ given mass of Cl}}{\text{ molar mass of Cl}}= \frac {31.77g}{35.5g/mole}=0.89moles$

Moles of O = $\frac {\text{ given mass of O}}{\text{ molar mass of O}}=\frac {57.34g}{16g/mole}=3.58moles$

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For Mg = $\frac {0.45}{0.45}=1$

For Cl = $\frac {0.89}{0.45}=2$

For O= $\frac {3.58}{0.45}=8$

The ratio of Mg :Cl : O= 1 : 2 : 8

Hence the empirical formula is $Mg_{1}Cl_{2}O_{8}$

4 0

3 years ago

A velocity-time graph shows how what changes over time?

finlep [7]

Answer:

A velocity-time graph shows how velocity changes over time. The sprinter's velocity increases for the first 4 seconds of the race, it remains constant for the next 3 seconds, and it decreases during the last 3 seconds after she crosses the finish line.

4 0

3 years ago

4P + 502 → 2P20x

Thepotemich [5.8K]

Answer:

5

Explanation:

According to the Law of Conservation of Matter, the mass of the products in a chemical reaction must equal the mass of the reactants.

5O2 = 10 Oxygen atoms

In 2POx there must be 10 Oxygen atoms too. => x = 5

...

Hope it can help you.

6 0

4 years ago

What is the % yield when 140.0 grams of Ethylene gas (C2H4) reacts with excess chlorine to form 280.0 grams of 1,2-Dichloro Etha

KatRina [158]

Answer:

percent yield = 56.6 %

Explanation:

Data given:

mass of Ethylene gas (C₂H₄) = 140 g

actual yield of 1,2-Dichloro Ethane (C₂H₄Cl₂)= 280 g

percent yield of 1,2-Dichloro Ethane (C₂H₄Cl₂) = ?

Reaction Given:

C₂H₄ + Cl₂ -------> C₂H₄Cl₂

Solution:

First we have to find theoretical yield.

So,

Look at the reaction

C₂H₄ + Cl₂ -----—> C₂H₄Cl₂

1 mol 1 mol

As 1 mole of C give 1 mole of CH₄

Convert moles to mass

molar mass of C₂H₄ = 2(12) + 4(1)

molar mass of C₂H₄ = 24 + 4

molar mass of C₂H₄ = 28 g/mol

molar mass of C₂H₄Cl₂ = 2(12) + 4(1) + 2(35.5)

molar mass of C₂H₄Cl₂ = 24 + 4 + 71

molar mass of C₂H₄Cl₂ = 99 g/mol

Now

C₂H₄ + Cl₂ -----—> C₂H₄Cl₂

1 mol (28 g/mol) 1 mol (99 g/mol)

28 g 99 g

28 grams of Ethylene gas (C₂H₄) produce 99 grams of C₂H₄Cl₂

So

if 28 g of C₂H₄ produce 99 g of C₂H₄Cl₂ so how many grams of C₂H₄Cl₂ will be produced by 140 g of C₂H₄.

Apply Unity Formula

28 g of C₂H₄ ≅ 99 g of C₂H₄Cl₂

140 g of C₂H₄≅ X of C₂H₄Cl₂

Do cross multiply

mass of C₂H₄Cl₂ = 99 g x 140 g / 28 g

mass of C₂H₄Cl₂ = 495 g

So the Theoretical yield of 1,2-Dichloro Ethane (C₂H₄Cl₂)= 495 g

Now Find the percent yield of 1,2-Dichloro Ethane (C₂H₄Cl₂)

Formula Used

percent yield = actual yield /theoretical yield x 100 %

Put value in the above formula

percent yield = 280g / 495 g x 100 %

percent yield = 56.6 %

percent yield of 1,2-Dichloro Ethane (C₂H₄Cl₂) = 56.6 %

8 0

4 years ago