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3 years ago

Need help with these two pls!!

Chemistry

1 answer:

denis23 [38]3 years ago

8 0

what is a fire piston?

*a tool for starting a fire, likely invented in Ancient Southeast Asia.*

dont know the second one lol.

You might be interested in

Can you tell me name of Chemicals in food?

Artyom0805 [142]

Answer:

Guar gum

sodium nitrite

artificial food colorings

monosodium glutamate

etc

6 0

2 years ago

Show All Work For Brainliest

sattari [20]

Answer:

1) 16.8 L CO2

2) 36.96 L NH3

3) 9.88 L CO2

4) 56.99 L H2O

Explanation:

How many liters of carbon dioxide gas will be produced when 75.0 g of calcium carbonate decomposes to form calcium oxide when at STP?

CaCO3 → CaO + CO2

Moles calcium carbonate = 75.0 grams / 100.09 g/mol

Moles calcium carbonate = 0.750 moles

For 1 mol CaCO3 we'll have 1 mol CaO and 1 mol CO2

For 0.750 moles CaCO3 we'll have 0.750 moles CO2

1 mol = 22.4 L

0.750 moles CO2 = 0.750 *22.4 L = 16.8 L CO2

2. Hydrogen gas reacts with 23.1 g of nitrogen gas to produce ammonia (NH3). What volume of ammonia will be produced at STP?

3H2 + N2 → 2NH3

Moles N2 = 23.1 grams / 28.0 g/mol

Moles N2 = 0.825 moles

For 3 moles H2 we need 1 mol N2 to produce 2 moles NH3

For 0.825 moles N2 we'll have 2*0.825 = 1.65 moles NH3

1 mol = 22.4 L

1.65 mol = 1.65 * 22.4 L = 36.96 L NH3

3. Iron (III) oxide reacts with carbon monoxide to form iron and carbon dioxide. How many liters of carbon dioxide will be produced from 23.5 g of iron (III) oxide when at STP?

Fe2O3 + 3CO → 2Fe + 3CO2

Moles Fe2O3 = 23.5 grams / 159.69 g/mol

Moles Fe2O3 = 0.147 moles

For 1 mol Fe2O3 we need 3 moles CO to produce 2 moles Fe and 3 moles CO2

For 0.147 moles Fe2O3 we'll have 3*0.147 = 0.441 moles CO2

1 mol = 22.4 L

0.441 moles = 22.4 * 0.441 = 9.88 L CO2

4.How many liters of water vapor would be produced in the combustion of 12.5L of ethane, C2H6 at STP?

2C2H6 + 7O2 →4CO2 + 6H2O

22.4 L = 1 mol

12.5 L = 0.848 moles C2H6

For 2 moles C2H6 we need 7 moles O2 to produce 4 moles CO2 and 6 moles H2O

For 0.848 moles C2H6 we'll have 3*0.848 = 2.544 moles H2O

1 mol = 22.4 L

2.544 moles = 22.4 L * 2.544 = 56.99 L H2O

5 0

3 years ago

Foods cook faster when placed in a pressure cooker. This is because the pressure on the surface of the water is (higher than/low

tia_tia [17]

Answer:

The pressure is higher than the atmospheric one, therefore the temperature is less.

Explanation:

When it is closed permanently, the pressure of the pot inside it increases, generating that the atoms and particles of the water are closer together, increasing their kinetic energy, if intermolecular friction and therefore the boiling point is lower, because the water reaches a boil or boil at a lower temperature.

5 0

2 years ago

A solution was prepared by mixing 20.00 mL of 0.100 M and 120.00 mL of 0.200 M. Calculate the molarity of the final solution of

Marat540 [252]

Answer:

0.186M

Explanation:

First, we need to obtain the moles of nitric acid that are given for each solution. Then, we need to divide these moles in total volume (120mL + 20mL = 140mL = 0.140L) to obtain molarity:

Moles Nitric acid:

0.0200L * (0.100mol / L) = 0.00200 moles

0.120L * (0.200mol / L)= 0.02400 moles

Total moles: 0.02400moles + 0.00200moles = 0.026 moles of nitric acid

Molarity: 0.026 moles / 0.140L

6 0

3 years ago

For the of freezing liquid ethanol at a given temperature and pressure,A. ΔH is positive and ΔS is positive.B. ΔH is positive an

Ksivusya [100]

Answer:

ΔH is negative and ΔS is negative.

Explanation:

Endothermic reaction -

The type of reaction in which energy is absorbed in the form of heat is known as endothermic reaction .

The reaction mixture usually get cooled after the reaction .( temperature decreases ) .

The sign of ΔH of an Endothermic reaction is positive .

For the of process of freezing the liquid ethanol , energy in the form of heat is released and hence , exothermic reaction ΔH is negative .

In the process of freezing , liquid is converted to solid , i.e. , the randomness reduces , and hence , entropy also decreases , hence , ΔS is negative .

3 0

3 years ago