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3 years ago

11

Pls help with this science homework

2 answers:

natka813 [3]3 years ago

3 0

These are all the answers. Hope I helped

1. A

2. C

3. A

4. B

TEA [102]3 years ago

3 0

I think it’s A C A B

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When water is heated in an ocean the liquid water changes from and turns into?

sasho [114]

Hello!

The answer is Evaporation

When you add heat to water, it boils, releasing gas into the air. This is called Evaporation. The water changes from a liquid to a gas.

Hope this helped!

6 0

3 years ago

Chlorine can be prepared in the laboratory by the reaction of manganese dioxide with hydrochloric acid, HCl(aq) , as described b

Nostrana [21]

Answer:

0.676 grams of manganese (IV) oxide should be added.

Explanation:

Moles of chlorine gas = n

Volume of the chlorine gas = V = 205 mL = 0.205 L

Pressure of the chlorine gas = 705 Torr = $\frac{705}{760}atm=0.928 atm$

1 atm = 760 Torr

Temperature of the chlorine gas = T = 25°C = 25 + 273 K = 298 K

$PV=nRT$ ( ideal gs equation)

$n=\frac{PV}{RT}=\frac{0.928 atm\times 0.205 L}{0.0821 atm L/mol K\times 298 K}=0.00777 mol$

$MnO_2(s)+4HCl(aq)\rightarrow MnCl_2(aq)+2H_2O(l)+Cl_2(g)$

According to reaction, 1 mole of chlorine gas is obtained from 1 mole of manganese(IV) oxide,then 0.00777 moles of chlorine gas will be obtained from :

$\frac{1}{1}\times 0.00777 mol=0.00777 mol$ of manganese (IV) oxide

Mass of 0.00777 moles of manganese (IV) oxide:

0.00777 mol × 87 g/mol = 0.676 g

0.676 grams of manganese (IV) oxide should be added.

3 0

3 years ago

0.378g grams of a compound is made up of 0.273g of Mg and 0.105g nitrogen. Find its empirical formula.

Harrizon [31]

Answer:

The empirical formula of the compound is $Mg_3N_2$ .

Explanation:

Mass of magnesium in compound = 0.273 g

Mass of nitrogen in the compound = 0.105 g

Moles of magnesium = $\frac{0.273 g}{24.305 g/mol}=0.0112 mol$

Moles of nitrogen = $\frac{0.105 g}{14.0067 g/mol}=0.00750 mol$

Form empirical formula divides the lowest value of moles of an element present with all the moles of elements present.

Magnesium $=\frac{0.0112 mol}{0.00750 mol}=1.5$

Nitrogen $=\frac{0.00750mol}{0.00750 mol}=1$

The empirical formula of a compound:

$Mg_{1.5}N_1=Mg_{\frac{15}{10}}N_1=Mg_{15}N_{10}=Mg_3N_2$

The empirical formula of the compound is $Mg_3N_2$ .

3 0

3 years ago

How many moles of Chromium are in 1.410 * 10 ^ 23 atoms of Chromium?

leva [86]

Answer:

<h3>The answer is 0.23 moles</h3>

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

$n = \frac{N}{L} \\$

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question we have

$n = \frac{1.410 \times {10}^{23} }{6.02 \times {10}^{23} } \\ = 0.234219...$

We have the final answer as

<h3>0.23 moles</h3>

Hope this helps you

4 0

3 years ago

Ben works as a medical assistant. He needs to take a patient's vitals, but the patient is refusing to cooperate. He hasn't exper

mariarad [96]

Answer:

THE CORRECT ANSWER IS COMMAND.HOPE IT HELP YOU

3 0

3 years ago