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3 years ago

How many molecules are in 3.5 moles of H2O A. 2.107x10^24 B. 3.87x10^24 C. 21.07 B. 1.72x10^23

Chemistry

1 answer:

Pani-rosa [81]3 years ago

8 0

Answer:

A. 2.107x10^24

Explanation:

1 mole is defined as the particles containing in 12g of 12-C. That is 6.022x10²³ particles.

When you say 1 mole of atoms means 6.022x10²³ atoms, 1 mole of molecules means 6.022x10²³ molecules, etc.

Now, 3.5 moles of H₂O are:

3.5mol * (6.022x10²³ molecules / 1mol) = 2.107x10²⁴ molecules of H₂O.

Thus, right answer is:

You might be interested in

How many number of moles are present in 200. g of sodium bicarbonate (NaHCO3)

nikdorinn [45]

You can solve this problem through dimensional analysis.

First, find the molar mass of NaHCO3.

Na = 22.99 g

H = 1.008 g

C = 12.01 g

O (3) = 16 (3) g

Now, add them all together, you end with with the molar mass of NaHCO3.

22.99 + 1.008 + 12.01 + 16(3) = 84.008 g NaHCO3. This number means that for every mole of NaHCO3, there is 84.008 g NaHCO3. In simpler terms, 1 mole NaHCO3 = 84.008 g NaHCO3.

After finding the molar mass of sodium bicarbonate, now you can use dimensional analysis to solve for the number of moles present in 200. g of sodium bicarbonate.

$200. g NaHCO_3 * \frac{1 mole NaHCO_3}{84.008 g NaHCO_3}$

Cross out the repeating units which are g NaHCO3, and the remaining unit is mole NaHCO3

200. * 1 = 200

200/ 84.008 = 2.38

Notice how there are only 3 sig figs in the answer. This is because the given problem only gave three sig figs.

Your final answer is 2.38 mol NaHCO3.

8 0

3 years ago

CAN SOMEONE HELP PLEASE!!!!!!!!!!!!!!!!!!!!!

aalyn [17]

Check for endorsements by celebrities of home-improvement shows.

4 0

3 years ago

What is the mass of a sample of alcohol (specific heat = 2.4 J/gC), if it requires 4780 J of heat to raise the temperature by 5.

insens350 [35]

The mass of a sample of alcohol is found to be = m = 367 g

Hence, it is found out that by raising the temperature of the given product, the mass of alcohol would be 367 g.

Explanation:

The Energy of the sample given is q = 4780

We are required to find the mass of alcohol m = ?

Given that,

The specific heat given is represented by = c = 2.4 J/gC

The temperature given is ΔT = 5.43° C

The mass of sample of alcohol can be found as follows,

The formula is c = $\frac{q}{mt}$

We can drive value of m bu shifting m on the left hand side,

m = $\frac{q}{ct}$

mass of alcohol (m) = $\frac{4780}{(2.4)( 5.43)}$

m = 367 g

Therefore, The mass of the given sample of alcohol is

m = 367g

It requires 4780 J of heat to raise the temperature by 5.43 C in the process which yields a mass of 367 g of alcohol.

4 0

4 years ago

Part A

KonstantinChe [14]

Answer:

The answer to your question is below

Explanation:

[H₃O⁺] = 2 x 10⁻¹⁴ M

pH = ?

Formula

pH = - log [H₃O⁺]

Substitution

pH = - log [2 x 10⁻¹⁴]

Result

pH = 13.7

[H₃O⁺] = ?

pH = 3.12

Formula

pH = - log [H₃O⁺]

Substitution

3.12 = - log [H₃O⁺]

$10^{-3.12} = [H_{3} O^{+}]$

Result

[H₃O⁺] = 7.59 M

7 0

3 years ago

Given the balanced equation representing a reaction at 101.3 kPa and 298 K:

ser-zykov [4K]

Answer (4)

Endothermic processes: are those in which occurs the absorption of heat.
the change of enthalpy (ΔH) is greater <span>than zero.
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hope this helps!

8 0

3 years ago