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Irina-Kira [14]
2 years ago
7

Explain why seeing a gas doesn not always indicate that there was a chemical change. ​

Chemistry
1 answer:
Orlov [11]2 years ago
7 0
A change of state (which is a physical change) can cause gas.
You might be interested in
When carbon is burned in air, it reacts with oxygen to form carbon dioxide. When 27.6 g of carbon were burned in the presence of
In-s [12.5K]

Answer:

The answer to your question is: 101.2 g of CO2

Explanation:

C = 27.6 g

O₂ = 86.5 g   remained 12.9 g

O₂ that reacted = 86.5 - 12.9 = 73.6 g

                     C     + O₂      ⇒        CO₂      The equation is balanced

                    27.6    73.6                 ?

MW               12        32                  44

Rule of three

                        12 g of C------------------  44 g  CO2

                       27.6 g C  ------------------    x

                  x = 27.6(44)/12 = 101.2 g of CO2

                       32 g of O2 ---------------    44 g of CO2

                        73.6 g of O2 ------------      x

                  x = 73.6(44)/32 = 101.2 g of CO2

6 0
3 years ago
PLEASE I NEED HELP ASAP!!!!
miv72 [106K]

The percent yield of the calcium hydroxide is 84.5%.

<h3>What is stoichiometry?</h3>

Stoichiometry enables us to obtain the mass of a substance form the equation of the reaction.

The equation of the reaction is;

CaCO3 + 2HCl -----> CaCl2 + CO2 + H2O

Number of moles of X = 40.0 grams/100 g/mol = 0.4 moles

Number of moles of HCl = 850/1000 * 1 M = 0.85 moles

If 1 mole of CaCO3 reacts with 2 moles of HCl

0.4 moles of  CaCO3 reacts with  0.4 moles  * 2 moles/1 mole

= 0.8 moles of HCl

Hence X is the limiting reactant.

The reaction is 1:1 then the amount of CO2  produced is 0.4 moles

Mass of CO2 = 0.4 CO2 * 44 g/mol = 17.6 g

2) The reaction equation is; 2NaOH + CaCO3 --->  Ca(OH)2 + Na2CO3

Number of moles of X = 25.0 grams/100 g/mol =  0.25 moles

Number of moles of NaOH= 40/1000 L * 2 M = 0.08 moles

If 1 mole of X reacts with 2 moles of NaOH

0.25 moles  reacts with   0.25 moles   * 2 moles /1 mole

= 0.5 moles

NaOH is the limiting reactant

2 moles of NaOH produces 1 mole of CO2

0.08 moles of NaOH produces 0.08 moles * 1 mole/2 moles

= 0.04 moles of CO2

Theoretical yield of CO2 =  0.04 moles of CO2 * 74 g/mol = 2.96  g

Percent yield = 2.5 g/ 2.96  g * 100

= 84.5%

Learn ore about percent yield:brainly.com/question/17042787

#SPJ1

5 0
1 year ago
Which of the following statements is true?
dybincka [34]

Answer:C

Explanation:

A process is called spontaneous if the process takes place on its own without the intervention of external factors.

The spontaneous processes are generally quick with observable rates of reaction.But processes can be spontaneous even with negligible rates of reaction.

Spontaneity of reactions depend on temperature.

This is because spontaneity is measured by gibbs energy or enthalpy.

Both of these measures are dependent on temperature.

So,temperature affects spontaneity.

7 0
2 years ago
HELP ME IK YOU GUYS ARE HELLA SMART
Bad White [126]

Answer:

1.200g

Explanation:

At the top it's 0 and that scale goes by 10s

The middle scale is 1 and it goes by 1s

The bottom scale is .2 and it goes by .1s

1+.2= 1.2 the extra zeroes are just place holders

1.200g

5 0
2 years ago
The hydrochloride form of cocaine has a solubility of 1.00 g in 0.400 mL water. Calculate the molarity of a saturated solution o
Tanya [424]

Answer:

The molarity of the solution is 7.4 mol/L

Explanation:

From the question above

0.400 ml of water contains 1.00 g of hydrochloride form of cocaine

Therefore 1000 ml of water will contain x g of hydrochloride form of cocaine

                    x = 1000 / 0.400

                    x = 2500 g

2500g of hydrochloride form of cocaine is present in 1000 ml of water.

Mole of hydrochloride form of cocaine = mass /molar mass of hydrochloride

Mole of hydrochloride form of cocaine = 2500/339.8

                                                                = 7.4 mol

Molarity = mol/ volume in liter (L)

molarity = 7.4 /1

Molarity = 7.4 mol/L

6 0
3 years ago
Read 2 more answers
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