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2 years ago

I really need help with this problem.

Chemistry

1 answer:

Aleksandr [31]2 years ago

8 0

Answer:

.371 mole of NaCl

Explanation:

Na Cl Mole weight = 22.989 + 35.45 = 58.439 g/mole

21.7 g / 58.439 g/mole = .371 mole

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An ideal gas in a cylindrical container of radius r and height h is kept at constant pressure p. The bottom of the container is

Juli2301 [7.4K]

Answer:

$m =\frac{p*(pi)*r^{2}*h*mw}{R*\frac{T_{1} + T_{O}}{2}}$

Explanation:

The gas ideal law is

PV= nRT (equation 1)

Where:

P = pressure

R = gas constant

T = temperature

n= moles of substance

V = volume

Working with equation 1 we can get

$n =\frac{PV}{RT}$

The number of moles is mass (m) / molecular weight (mw). Replacing this value in the equation we get.

$\frac{m}{mw} =\frac{PV}{RT}$ or

$m =\frac{P*V*mw}{R*T}$ (equation 2)

The cylindrical container has a constant pressure p

The volume is the volume of a cylinder this is

$V =(pi)*r^{2}*h$

Where:

r = radius

h = height

(pi) = number pi (3.1415)

This cylinder has a radius, r and height, h so the volume is $V =(pi)*r^{2}*h$

Since the temperatures has linear distribution, we can say that the temperature in the cylinder is the average between the temperature in the top and in the bottom of the cylinder. This is:

$T =\frac{T_{1} + T_{O}}{2}$

Replacing these values in the equation 2 we get:

$m =\frac{P*V*mw}{R*T}$ (equation 2)

$m =\frac{p*(pi)*r^{2}*h*mw}{R*\frac{T_{1} + T_{O}}{2}}$

8 0

4 years ago

Which change absorbs heat?

tekilochka [14]

Freezing water into ice

7 0

3 years ago

Read 2 more answers

Is math involved in basketball? and how?

ra1l [238]

Answer:

yes

Explanation:

math is used constantly to improve one's performance. Achieving the objective of shooting a basketball includes using percentages and angles. By finding the most consistent percentage of shots made while using a certain angle, you can find out which player will score the most baskets.

8 0

3 years ago

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When 70.4 g of benzamide (C7H7NO) are dissolved in 850. g of a certain mystery liquid X , the freezing point of the solution is

lora16 [44]

Answer:

i=1.62 .

Explanation:

Let, i be the Van't Hoff Factor.

Moles of benzamide,= $\dfrac{Mass}{molar\ mass}=\dfrac{70.4}{121.14}=0.58\ mol.$

Molality of solution, m= $\dfrac{moles }{mass\ of\ solvent}=\dfrac{0.58}{0.85}=0.68\ molal.$

Now, we know

Depression in freezing point, $\Delta T=i\times K_f\times m$ .....1

It is given that,

$\Delta T=2.7^o C\\i=1 ( since\ it\ is\ non\ dissociable\ solutes)\\K_f ( freezing\ constant)\\$

Putting all these values we get,

$K_f=3.949\ C/m.$

Now, moles of ammonium chloride= $\dfrac{70.4}{53.49}=1.316\ mol.$

molality = $\dfrac{1.316}{0.85}=1.54 molal.\\\Delta T=9.9 .$

Putting all these values in eqn 1.

We get,

i=1.62 .

Hence, this is the required solution.

6 0

3 years ago

1. What volume of gas (NU) is formed by the interaction of 13 g of zinc with 400 g of sulfuric acid solution with a mass fractio

Svetllana [295]

Answer:

4.5L of gas are produced

Explanation:

Based on the reaction:

Zn + H2SO4 → ZnSO4 + H2(g)

Where 1 mole of Zn reacts with 1 mole of sulfuric acid to produce 1 mole of H2, the gas

To solve this question we must find the moles of each reactant in order to find limiting reactant and, thus, the moles of H2 produced. Then using PV=nRT we can find the volume of the gas:

Moles Zn -Molar mass: 65.38g/mol-

13g * (1mol / 65.38g) = 0.20 moles Zn

Moles H2SO4 -Molar mass: 98g/mol-

400g * 10% = 40g H2SO4 * (1mol / 98g) = 0.41 moles H2SO4

As the ratio of the reaction is 1:1, the limiting reactant is Zn and the moles produced of H2 are 0.20 moles

Using PV = nRT; V = nRT/ P

Where V is the volume of the gas

n are the moles = 0.20 moles

R is gas constant = 0.082atmL/molK

T is absolute temperature = 273.15K at STP

P is pressure = 1atm at STP

V = 0.20mol*0.082atmL/molK*273.15K / 1atm

V = 4.5L of gas are produced

5 0

3 years ago