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2 years ago

Which of the following statements is most accurate?

Chemistry

1 answer:

Troyanec [42]2 years ago

4 0

Answer:

Explanation:

This is because exothermic reactions occurs when bnds are formed, and involves the release of energy.

Endothermic reaction occur when bonds are broken,and involves absorption of energy.

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What are the amount of moles in 12.15 grams of Magnesium?

zaharov [31]

I think the amount would be a 0.4998 mol
I did moles=mass(g)/A,r
=12.5/24.3 to get that

8 0

2 years ago

Aqueous sulfuric acid reacts with solid sodium hydroxide to produce aqueous sodium sulfate and liquid water . If of sodium sulfa

notka56 [123]

Answer:

27%

Explanation:

Hello,

The following information is missing, but I found it: "1.92 g of sodium sulfate is produced from the reaction of 4.9 g of sulfuric acid and 7.8 g of sodium hydroxide" so the undergoing chemical reaction is:

$2NaOH+H_2SO_4-->Na_2SO_4+2H_2O$

Now, to compute the percent yield, we must first establish the limiting reagent to subsequently determine the theoretical yield of sodium sulfate because the real (1.92g) is already given, thus, we consider the following procedure:

$n_{NaOH}=7.8gNaOH*\frac{1molNaOH}{40gNaOH}=0.2molNaOH\\n_{H_2SO_4}=4.9gH_2SO_4*\frac{1molH_2SO_4}{98gH_2SO_4}=0.050molH_2SO_4\\$

- The moles of sodium hydroxide that completely react with 0.05 moles of sulfuric acid are:

$0.2molNaOH*\frac{1molH_2SO_4}{2molNaOH}=0.098molH_2SO_4$

As this number is higher than the previously computed 0.05 moles of available sulfuric acid, one states that the sulfuric acid is the limiting reagent. Now, the theoretical grams of sodium sulfate are found via:

$0.05molH_2SO_4*\frac{1molNa_2SO_4}{1mol H_2SO_4} *\frac{142.04gNa_2SO_4}{1molNa_2SO_4} =7.1gNa_2SO_4$

Finally, the percent yield turns out into:

$Y=\frac{1.92g}{7.1g} *100$

$Y=27.0$ %

Best regards.

6 0

2 years ago

Aspirin tablets contain the active ingredient (aspirin) and various inactive ingredients. Suggest what types of inactive ingredi

Debora [2.8K]

Binders ; fillers. They are inert substances to hold pill shape and preserve the medication, its ph / etc.

5 0

2 years ago

Explain why the standard enthalpy of formation () for Cl2 (g) is zero, but its standard entropy is larger than zero.

Galina-37 [17]

The standard enthalpy of formation for chlorine is zero but the standard entropy is larger than 0 because it is the elemental state of chlorine.

The standard enthalpy of formation for chlorine is zero because cl2 is the elemental state of chlorine and it does not require any energy for the formation of the standard state of chlorine.

The entropy of any system cannot be negative. It can only be positive or zero.

The entropy of a system will become zero only at a absolute zero temperature.

That's why the entropy of chlorine in elemental state is more than zero because absolutely zero temperature can't be obtained.

To know more about entropy, visit,

brainly.com/question/6364271

#SPJ4

7 0

5 months ago

Amphetamine (C9H13N) is a weak base with a pKb of 4.2.

QveST [7]

Weak base: [OH⁻] = √Kb.C

pKb = 4.2

$\tt Kb=10^{-4.2}$

c = concentration

MM Amphetamine (C9H13N) = 135.21 g/mol

c = 215 mg/L = (0.215 g : 135,21 g/mol) / L = 0.00159 mol/L = 1.59 x 10⁻³ mol/L

$\tt [OH^-]=\sqrt{10^{-4.2}\times 1.59\times 10^{-3}}=3.17\times 10^{-4}$

pOH = 4 - log 3.17

pH = 14 - (4 - log 3.17)

pH = 10 + log 3.17 = 10.50

4 0

2 years ago