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3 years ago

What is the mass in grams of 5.25 x 1024 molecules of NaOH?

Chemistry

1 answer:

Colt1911 [192]3 years ago

4 0

Answer: The mass is 348.8g

Explanation:

We begin by using Avogadro's number to convert the number of molecules of Sodium Hydroxide to moles.

6.02 x 10∧23 molecules of NaOH -------> 1 mole of NaOH

∴ 5.25 x 10∧24 molecules of NaOH -------> 1/ 6.02 x 10∧23 x 5.25 x 10∧24 =

8.72moles.

Having found the number of moles, we then move from moles to gram by using the molar mass of NaOH (i.e the mass of 1 mole of NaOH).

1 mole of NaOH is equivalent to 40g (Molar Mass)

8.72 moles of NaOH would be equivalent to; 40/ 1 x 8.72 = 348.8g

The mass in 5.25 x 10∧24molecules of NaOH is 348.8g

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How many grams of aluminum are required to react with 35 mL of 2.0 M hydrochloric acid, HCl?__ HCl + __ Al --> __ AlCl3 + __

kiruha [24]

Answer:

0.6258 g

Explanation:

To determine the number grams of aluminum in the above reaction;

determine the number of moles of HCl
determine the mole ratio,
use the mole ratio to calculate the number of moles of aluminum.
use RFM of Aluminum to determine the grams required.

Moles of HCl

35 mL of 2.0 M HCl

2 moles of HCl is contained in 1000 mL

x moles of HCl is contained in 35 mL

$x \: mol \: = \: \frac{2 \: \times \: 35}{1000} \\ = 0.07 \: moles \:$

We have 0.07 moles of HCl.

Mole ratio

Balanced equation

6HCl(aq) + 2Al(s) --> 2AlCl3(aq) + 3H2(g)

Hence mole ratio = 6 : 2 (HCl : Al

but moles of HCl is 0.07, therefore the moles of Al;

$= \frac{2}{6} \times 0.07 \\ \: = 0.0233333 \: moles$

Therefore we have 0.0233333 moles of aluminum.

Grams of Aluminum

We use the formula;

$grams \: = moles \: \times \: rfm$

The RFM (Relative formula mass) of aluminum is 26.982g/mol.

Substitute values into the formula;

$= 0.0233333 \: moles \: \times \: 26.982 \: \frac{g}{mol} \\ = 0.625799 \: grams$

The number of grams of aluminum required to react with HCl is 0.6258 g.

3 0

2 years ago

Calculate the number of ammonia molecules in 3.9 g.

disa [49]

•3.9g of ammonia
•molar mass of ammonia = 17.03g/mol

1st you have to covert grams to moles by dividing the mass of ammonia with the molar mass:

(3.9 g)/ (17.03g/mol) = 0.22900763mols

Then convert the moles to molecules by multiplying it with Avogadro’s number:

Avogadro’s number: 6.022 x 10^23

0.22900763mols x (6.022 x 10^23 molecs/mol)
= 1.38 x 10^23 molecules

6 0

3 years ago

A sample of gas initially has a volume of 2.25 L at 350 K and a pressure of 1.75 atm. What will be sample pressure if the volume

IRINA_888 [86]

Answer:

8.44 atm

Explanation:

From the question given above, the following data were obtained:

Initial volume (V₁) = 2.25 L

Initial temperature (T₁) = 350 K

Initial pressure (P₁) = 1.75 atm

Final volume (V₂) = 1 L

Final temperature (T₂) = 750 K

Final pressure (P₂) =?

The final pressure of the gas can be obtained as illustrated below:

P₁V₁/T₁ = P₂V₂/T₂

1.75 × 2.25 / 350 = P₂ × 1 / 750

3.9375 / 350 = P₂ / 750

Cross multiply

350 × P₂ = 3.9375 × 750

350 × P₂ = 2953.125

Divide both side by 350

P₂ = 2953.125 / 350

P₂ = 8.44 atm

Thus, the final pressure of the gas is 8.44 atm.

7 0

3 years ago

I. Give the name for the following compounds:

alexandr402 [8]

Answer:

Explanation:

1) MgBr₂

Magnesium bromide

2) Ca₃(PO₄)₂

Calcium phosphate

3) NO₂

Nitrogen dioxide

4) Ni₂(CO₃)₃

Nickel(III) carbonate

5) (NH₄)₂CO₃

Ammonium carbonate

6) MnBr₂

Manganese bromide

7) Na[MnO₄]

Sodium permanganate

8) P₂O₅

Phosphorus pentoxide

9) CCl₄

Carbon tetrachloride

10) Fe(OH)₂

Iron(ii) hydroxide

8 0

3 years ago

Why are the transition metals not isoelectronic with noble gas atoms?

V125BC [204]

The atoms and ions that have the similar electron configuration are named isoelectronic. The common ions of representative elements are isoelectronic with a noble gas. When forming ions, transition metals be unable to find their valence s-sublevel electrons before they lose their d-sub level electrons.

8 0

3 years ago