Weigh 4.5 grams of sodium hydroxide and add it to the dry volumetric flask of 450 mL followed by small amount of water to dissolve all the NaOH .After this add the water upto tye mark of 450 mL.

Explanation:

Molarity of the solution is the moles of compound in 1 Liter solutions.

$Molarity=\frac{\text{Mass of compound}}{\text{Molar mas of compound}\times Volume (L)}$

Mass of NaOH = x

Molar mass of NaOH = 40 g/mol

Volume of the NaOH solution = 450 mL =- 0.450 L ( 1 ml = 0.450 L)

Molarity of the solution of NaOH = 0.250 M

$Molarity=\frac{1.248 g}{26 g/mol\times 0.9102254 L}=0.528 mol/L$

$0.250 M=\frac{x}{40 g/mol\times 0.450 L}$

Solving for x:

x = 4.5 g

Weigh 4.5 grams of sodium hydroxide and add it to the dry volumetric flask of 450 mL followed by small amount of water to dissolve all the NaOH .After this add the water upto tye mark of 450 mL.

4 0

3 years ago

Calculate the number of moles in the following: 2.8 X 10^24 atoms of Cl2

vova2212 [387]

Answer:

<h3>The answer is 4.65 moles</h3>

Explanation:

To find the number of moles given it's number of entities we use the formula

$n = \frac{N}{L} \\$

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question

N = 2.8 × 10²⁴ atoms of Cl2

So we have

$n = \frac{2.8 \times {10}^{24} }{6.02 \times {10}^{23} } \\ = 4.65116279069...$

We have the final answer as

<h3>4.65 moles</h3>

Hope this helps you

7 0

3 years ago

Determine the number of molecules in a 100. gram sample of CCl4

enyata [817]

100. g CCl4* (1 mol CCl4/ 153.8 g CCl4)* (6.02*10^23 CCl4 molecules/ 1 mol CCl4)= 3.91*10^23 CCl4 molecules.
(Note that the units cancel out so you get the answer)

Hope this helps~

8 0

3 years ago

according to the kinetic molecular theory the pressure exerted by a sample of gas at constats volume doubles when the absolute t

ozzi

Answer: gas molecules will hit the container walls more frequently and with greater force

Explanation:

According to the postulates of kinetic molecular theory:

1. The pressure exerted by a gas in a container results from collisions between the gas molecules and the container walls.

2. The average kinetic energy of the gas molecules is proportional to the kelvin temperature of the gas.

When the temperature is increased, so the average kinetic energy and the rms speed also increase. This means that the gas molecules will hit the container walls more frequently and with greater force because they are all moving faster. This increase the pressure.

7 0

3 years ago