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2 years ago

Identify and calculate the number of representative particles in 2.15 moles of gold.

Chemistry

1 answer:

LekaFEV [45]2 years ago

5 0

Answer:

$1.29 * 10^{24}$ particles of gold

Explanation:

To convert the number of moles of any substance, in this case gold, you need Avogadro's number.

Avogadro's number is always $6.022$ × $10^{23}$

$2.15$ moles Au × $\frac{6.022*10^{23} particles}{1 mole Au}$ = $1.29 * 10^{24}$ particles of gold

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In the Acid-Base Chemistry Experiment the measurement of pH will be used to explore acid-base concepts, analyze an unknown, and

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Answer

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Doing the calculus of pH

$pH= -Log [H^{+}] = -Log (0.00045)$

b) pH is a way to express the hydronium concentration over a wide range. True

pH means –Log[H+] and this value is used to express a wide range of hydronium concentration sometimes obtaining pH minor than zero.

c) Percent K and Fe are determined by doing ion exchange then a pH titration. False

Usually, Fe is determined by redox titration with potassium permanganate due to it’s more accurate. On the other hand, K is determined usually by volumetric process which includes precipitation like potassium picrate precipitate

d) About 0.2M HCl is the reagent used for the pH titrations. False.

In order to do pH titration, it is possible to use a wide range of HCl concentrations and other acids as reagent if the analyte is a basic compound. Otherwise, if the analyte is an acid compound you should use a basic compound as reagent.

e) A Lewis base is specie that can donate a proton to an acid. False

A Lewis base is an electron pair donor.

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2 years ago

Write an equation that represents the action in water of rubidium hydroxide as an Arrhenius base.

Anika [276]

Answer:

RbOH → Rb⁺ + OH⁻

As the hydroxide can gives the OH⁻ in water, it is considered as an Arrhenius's base

Explanation:

Arrhenius theory states that a compound is considered a base, if the compound can generate OH⁻ ions in aqueous solution.

Our compound is the RbOH.

When it is put in water, i can dissociate like this:

RbOH → Rb⁺ + OH⁻

As the hydroxide can gives the OH⁻ in water, it is considered as an Arrhenius's base

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2 years ago

Nicole has 2 glasses on the counter: one of water and one of sugar. She is baking a cake and needs to use the sugar-water for th

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Answer:It is a mixture

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2 years ago

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The air bags in cars are inflated when a collision triggers the explosive, highly exothermic decomposition of sodium azide (NaN3

Oksanka [162]

Answer : The mass of $NaN_3$ required is, 166.4 grams.

Explanation :

First we have to calculate the moles of nitrogen gas.

Using ideal gas equation:

$PV=nRT$

where,

P = Pressure of $N_2$ gas = 1.00 atm

V = Volume of $N_2$ gas = 113 L

n = number of moles $N_2$ = ?

R = Gas constant = $0.0821L.atm/mol.K$

T = Temperature of $N_2$ gas = $85^oC=273+85=358K$

Putting values in above equation, we get:

$1.00atm\times 113L=n\times (0.0821L.atm/mol.K)\times 358K$

$n=3.84mol$

Now we have to calculate the moles of sodium azide.

The balanced chemical reaction is,

$2NaN_3(s)\rightarrow 2Na(s)+3N_2(g)$

From the balanced reaction we conclude that

As, 3 mole of $N_2$ produced from 2 mole of $NaN_3$

So, 3.84 moles of $N_2$ produced from $\frac{2}{3}\times 3.84=2.56$ moles of $NaN_3$

Now we have to calculate the mass of $NaN_3$

$\text{ Mass of }NaN_3=\text{ Moles of }NaN_3\times \text{ Molar mass of }NaN_3$

Molar mass of $NaN_3$ = 65 g/mole

$\text{ Mass of }NaN_3=(2.56moles)\times (65g/mole)=166.4g$

Therefore, the mass of $NaN_3$ required is, 166.4 grams.

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2 years ago

When the reaction mixture is worked-up, it is first washed three times with 5% sodium bicarbonate, and then with a saturated nac

Ann [662]

Solution:

After the reaction of mixture is worked-up Washing three times the organic with sodium carbonate helps to decrease the solubility of the organic layer into the aqueous layer. This allows the organic layer to be separated more easily.

And then the reaction washed by saturated NACL we have The bulk of the water can often be removed by shaking or "washing" the organic layer with saturated aqueous sodium chloride (otherwise known as brine). The salt water works to pull the water from the organic layer to the water layer.

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2 years ago

Identify and calculate the number of representative particles in 2.15 moles of gold.​

Identify and calculate the number of representative particles in 2.15 moles of gold.