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3 years ago

Which of the following can be mixed in solution with H2CO3 to make a buffer?

Chemistry

1 answer:

Temka [501]3 years ago

8 0

Answer:

Sodium hydroxide solution.

Explanation:

because it is a strong base. Since carbonic acid is a weak acid, a solution formed resists change in pH on addition hence buffer formed.

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What are "representative elements"?

Mars2501 [29]

Answer: c. elements in the same row of the periodic table

Explanation: It kind of represents a graph of the periodic table

8 0

3 years ago

Read 2 more answers

A student reacts 5.0 g of sodium with 10.0 g of chlorine and collect 5.24 g of sodium chloride. What is the percent yield of thi

Ede4ka [16]

Answer: The percent yield of this combination reaction is 41.3 %

Explanation : Given,

Mass of $Na$ = 5.0 g

Mass of $Cl_2$ = 10.0 g

Molar mass of $Na$ = 23 g/mol

Molar mass of $Cl_2$ = 71 g/mol

First we have to calculate the moles of $Na$ and $Cl_2$ .

$\text{Moles of }Na=\frac{\text{Given mass }Na}{\text{Molar mass }Na}$

$\text{Moles of }Na=\frac{5.0g}{23g/mol}=0.217mol$

and,

$\text{Moles of }Cl_2=\frac{\text{Given mass }Cl_2}{\text{Molar mass }Cl_2}$

$\text{Moles of }Cl_2=\frac{10.0g}{71g/mol}=0.141mol$

Now we have to calculate the limiting and excess reagent.

The balanced chemical equation will be:

$2Na+Cl_2\rightarrow 2NaCl$

From the balanced reaction we conclude that

As, 2 mole of $Na$ react with 1 mole of $Cl_2$

So, 0.217 moles of $Na$ react with $\frac{0.217}{2}=0.108$ moles of $Cl_2$

From this we conclude that, $Cl_2$ is an excess reagent because the given moles are greater than the required moles and $Na$ is a limiting reagent and it limits the formation of product.

Now we have to calculate the moles of $NaCl$

From the reaction, we conclude that

As, 2 mole of $Na$ react to give 2 mole of $NaCl$

So, 0.217 mole of $HCl$ react to give 0.217 mole of $NaCl$

Now we have to calculate the mass of $NaCl$

$\text{ Mass of }NaCl=\text{ Moles of }NaCl\times \text{ Molar mass of }NaCl$

Molar mass of $NaCl$ = 58.5 g/mole

$\text{ Mass of }NaCl=(0.217moles)\times (58.5g/mole)=12.7g$

Now we have to calculate the percent yield of this reaction.

Percent yield = $\frac{\text{Actual yield}}{\text{Theoretical yield}}\times 100$

Actual yield = 5.24 g

Theoretical yield = 12.7 g

Percent yield = $\frac{5.24g}{12.7g}\times 100$

Percent yield = 41.3 %

Therefore, the percent yield of this combination reaction is 41.3 %

4 0

4 years ago

A gas with a vapor density greater than that of air, would be most effectively displaced out off a vessel by?

AURORKA [14]

A gas with a vapor density greater than that of air, would be most effectively displaced out off a vessel by ventilation.

The two following principles determine the type of ventilation: Considering the impact of the contaminant's vapour density and either positive or negative pressure is applied.

Consider a vertical tank that is filled with methane gas. Methane would leak out if we opened the top hatch since its vapour density is far lower than that of air. A second opening could be built at the bottom to greatly increase the process' efficiency.

A faster atmospheric turnover would follow from air being pulled in via the bottom while the methane was vented out the top. The rate of natural ventilation will increase with the difference in vapour density. Numerous gases that require ventilation are either present in fairly low concentrations or have vapor densities close to one.

3 0

2 years ago

An isotonic salt solution is 0.90% (w/w) nacl in water. how many grams of nacl are contained in 1.00 kg of such a solution?

Fed [463]

An isotonic salt solution is 0.90% (w/w) nacl in water many grams of nacl are contained in 1.00 kg of such a solution Reconstruction debate that had federalism debate that had been an issue since the 1790s.

Reconstruction failed by most other measures: Radical Republican legislation ultimately failed to isotonic former slaves from white persecution and failed to engender fundamental changes to the social fabric of the South. When President Rutherford B. federalism debate that had been an issue since the 1790s almost mediately . Hayes removed federal troops from isotonic South in 1877, former Confederate officials and slave returned to With the support of a conservative Supreme Court, these newly empowered white southern politicians passed black codes, voter qualifications, and other anti-progressive legislation to reverse the rights that blacks had gained during Radical Reconstruction. The U.S. Supreme Court bolstered this federalism anti-progressive movement federalism with decisions in the Slaughterhouse Cases, the Civil Rights Cases, and United States v.

Learn more about Reconstruction on:

brainly.com/question/24761999

#SPJ4

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2 years ago

Hydrocyanic acid, HCN, is a weak acid. (a) Write the chemical equation for the dissociation of HCN in water. (b) Identify the Br

12345 [234]

Answer: a) $HCN(aq.)+H_2O\rightleftharoons H_3O^+(aq.)+CN^-(aq.)$

b) $HCN$ : acid $CN^-$ :conjugate base.

And, $H_2O$ : base $H_3O^+$ : conjugate acid.

c) $HCN(aq.)+NaOH(aq)\rightleftharoons NaCN(aq.)+H_2O(l)$

d) $NaCN(aq)\rightarrow Na^+(aq.)+CN^-(aq)$

e) $NaCN(aq)+HCl(aq)\rightarrow NaCl(aq.)+HCN(aq)$

Explanation:

a) Weak acid is defined as the acid which does not completely dissociates when dissolved in water. They have high pH. These releases $H^+$ ions in their aqueous states.

The equation for the dissociation of $HCN$ acid is given by:

$HCN(aq.)+H_2O\rightleftharoons H_3O^+(aq.)+CN^-(aq.)$

b) According to the Bronsted-Lowry conjugate acid-base theory, an acid is defined as a substance which looses donates protons and thus forming conjugate base and a base is defined as a substance which accepts protons and thus forming conjugate acid.

For the given chemical equation:

$HCN$ is loosing a proton, thus it is considered as an acid and after losing a proton, it forms $CN^-$ which is a conjugate base.

And, $H_2O$ is gaining a proton, thus it is considered as a base and after gaining a proton, it forms $H_3O^+$ which is a conjugate acid.

c) Neutralization reaction is a reaction in which an acid reacts with base to produce salt and water.

$HCN(aq.)+NaOH(aq)\rightarrow NaCN(aq.)+H_2O(l)$

d) The chemical equation for dissociation of $NaCN$ in water.

$NaCN(aq)\rightarrow Na^+(aq.)+CN^-(aq)$

e) The chemical equation for the reaction of $NaCN$ and $HCI$

$NaCN(aq)+HCl(aq)\rightarrow NaCl(aq.)+HCN(aq)$

4 0

3 years ago