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3 years ago

What is the atomic mass for Helium (He)? Question 5 options: 8 2 3 4

1 answer:

3 0

It is 2 because if you have a chart that shown all the elements at the top left corner it would show a number and that is the atomic number

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To study a key fuel-cell reaction, a chemical engineer has 20.0-L tanks of H₂ and of O₂ and wants to use up both tanks to form 2

Lapatulllka [165]

the pressure needed on H2 tank is 34.9477319atm and the pressure needed in O2 tanks is 16.7690007atm .

Given , to study a key fuel-cell reaction , a chemical engineer has 20.0L tanks of H2 and O2 and wants to use up both tanks to form 28.0mol of water at 23.8°C .

the reaction of the fuel cell is given by ,

H2(g) +1/2 O2 ( g) →H2O

Moles of H2 required = 28 mol

moles of O2 required = 14mol

Now according to van der waals equation ,

p= (nRT/ V-nb) - an^2 / V^2

for H2 , a = 0.2453L^2bar /mol^2 , b= 0.02651L/mol

P for H2

= (28×0.0821×296.8/20-28×0.02651 ) -(0.2456 ×28×28/20×20)

P for H2 = 35.4291079-0.481376 = 34.9477319 atm

for O2 , a = 1.38L^2bar/mol^2 , b = 0.03186L/mol

P for O2 = (14×0.0821×296.8 /20-14×0.03186) - (1.382×14×14/20×20)

P for O2 = 17.4461807 - 0.67718 =16.7690007 atm

Hence , the pressure needed on H2 tank is 34.9477319atm and the pressure needed in O2 tanks is 16.7690007atm .

Learn more about pressure here :

brainly.com/question/25965960

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6 0

1 year ago

Which is the correctly balanced chemical equation for the reaction of KOH and H2SO4? Upper K upper O upper H right arrow upper H

sertanlavr [38]

Answer :

The balanced chemical reaction will be,

$H_2SO_4+2KOH\rightarrow K_2SO_4+2H_2O$

Explanation :

Balanced chemical reaction : It is defined as the reaction in which the number of atoms of individual elements present on reactant side must be equal to the product side.

If the amount of atoms of each type on the left and right sides of a reaction differs then to balance the equation by adding coefficient in the front of the elements or molecule or compound in the chemical equation.

The coefficient tell us about that how many molecules or atoms present in the chemical equation.

When sulfuric acid react with potassium hydroxide then it react to give potassium sulfate and water as a product. This reaction is known as acid-base reaction.

The balanced chemical reaction will be,

$H_2SO_4+2KOH\rightarrow K_2SO_4+2H_2O$

4 0

3 years ago

Read 2 more answers

Please help<br>............

Levart [38]

Answer:

Explanation:

An ammeter, a voltmeter. The third one i didnt know it

3 0

3 years ago

Which source of energy causes most of the water evaporation on Earth’s surface?

elena-s [515]

The heat energy that causes most of the water evaporate on the surface of the Earth is the Sun. Which provides earth most of the thermal energy into the hydro-thermodynamic system on Earth.

{{Sun}}

8 0

3 years ago

How many moles of solute are contained in 200 milliliters of a 1 M solution?

lorasvet [3.4K]

The answer is (2) 0.2. The unit of M means 1 mol/L. The conversion of liter and milliliter is 1 liter equals 1000 milliliters. So the molar number of solute is 1*0.2=0.2 mol.

5 0

3 years ago