All categories

3 years ago

0.7 L of H2 enters a reaction at standard temperature and pressure.

Chemistry

1 answer:

ASHA 777 [7]3 years ago

6 0

Answer:

1.88 × 10²³ particles

Explanation:

Given data:

Volume of H₂ = 0.7 L

Number of particles at STP = ?

Solution:

First of all we will calculate the number of moles of H₂.

PV = nRT

n = PV / RT

n = 1 atm . 7 L / 0.0821 L. atm. mol⁻¹. k⁻¹ × 273.15 K

n = 7 atm. L / 22.43 L. atm. mol⁻¹

n = 0.312 mol

it is known that,

2 g H₂ = 1 mol = 6.022 × 10²³ particles

For 0.312 mol

0.312 × 6.022 × 10²³ particles

1.88 × 10²³ particles

You might be interested in

ASAPPPPP<br> how do 2 positive charge move in an electric field

Luden [163]

Answer:

yer

Explanation:

4 0

3 years ago

A barrel of crude oil has a volume of 42 gallons, only approximately 45% of which is processed into gasoline. If your car achiev

balandron [24]

Answer:

The number of barrels of crude oil required to run the car for a year is 52.9 barrels of crude oil

Explanation:

The information given are as follows;

Percentage of crude oil processed into gasoline = 45%

Distance achieved per gallon by car = 36 mi/gal

Distance driven per year = 36,000 miles

$Gasoline\, usage \, in \, one \, year = \dfrac{Distance \ driven\ per \ year }{Distance\ achieved \ per gallon \ by \ car } = \dfrac{36000\, miles}{36\, miles/gallon}$ $\dfrac{36000\, miles}{36\, miles/gallon} = 1000 \, gallons$

∴ Gasoline usage in one year = 1,000 gallons

Percentage of crude oil processed into gasoline = 45%

Hence, where 45% of the crude oil produces 1000, the volume of crude, x, from which the gasoline is sourced becomes;

x × 45/100 = 1000 gallons

x =100 × 1000/45 = 20000/9 gallons of crude

1 barrel of crude oil is approximately 42 gallons of crude oil

∴ 20000/9 gallons of crude = 20000/(9×42) barells of crude = 10000/

Which gives;

$52\tfrac{172}{189} \, barrels \, of \, crude \, oil$

Which is 52.9 barrels of crude oil

Hence the number of barrels of crude oil required to run the car for a year = 52.9 barrels of crude oil.

4 0

3 years ago

7. What is the mass of a piece of copper (Cu) that undergoes a 25.0 °C

Olegator [25]

Answer:

0.0428 kg or 42.8 g

Explanation:

Applying,

Q = cmΔt.............. Equation 1

Where Q = heat lost of heat gained, c = specific heat capacity of copper, m = mass of copper, Δt = temperature change.

make m the subject of the equation above

m = Q/cΔt.................. Equation 2

From the question,

Given: Q = 428 J, Δt = 25 °C

Constant: c = 400 J/kg.°C

Substitute these values into equation 2

m = 428/(25×400)

m = 0.0428 kg

m = 42.8 g

3 0

3 years ago

Convert 92.92 g NaOH to moles

user100 [1]

Answer:

It would be 2.323167848877082

Explanation:

3 0

3 years ago

A 5.22 × 10−3−mol sample of HY is dissolved in enough H2O to form 0.088 L of solution. If the pH of the solution is 2.37, what i

OleMash [197]

Answer:

3.07 × 10⁻⁴

Explanation:

Step 1: Calculate the concentration of H⁺

We will use the definition of pH.

$pH = -log [H^{+} ]\\\[ [H^{+} ] = antilog -pH = antilog -2.37 = 4.27 \times 10^{-3} M$

Step 2: Calculate the concentration of HY

5.22 × 10⁻³ mol of HY are dissolved in 0.088 L. The concentration of the acid (Ca) is:

$Ca = \frac{5.22 \times 10^{-3} mol }{0.088L} = 0.0593M$

Step 3: Calculate the acid dissociation constant (Ka)

We will use the following expression.

$Ka = \frac{[H^{+}]^{2} }{Ca} = \frac{(4.27 \times 10^{-3} )^{2} }{0.0593} = 3.07 \times 10^{-4}$

6 0

3 years ago