1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
chubhunter [2.5K]
3 years ago
12

Hydrogen and oxygen combine in the ratio of 1:8 by mass to form water. How many grams of hydrogen are needed to react completely

with 6.4 g of oxygen gas? Show complete working. Which law of chemical combination will govern your answer? Write the law.
Chemistry
1 answer:
kondor19780726 [428]3 years ago
7 0

Explanation: Number of moles of water = mass of water/ molar mass.  

Molar mass of H2O = (1*2) + 16 = 18.0  

 Now we only need to calculate the number of moles of water.  

The chemical reaction is as follows  

CH4 + 2O2 ---> CO2 + 2H2O  

From the eqn, the moles of H2O = 2*moles of CH4  

Molar mass of CH4 = 12 + 4 = 16. Number of moles of methane = mass/

molar mass.   No of moles = 6.4/16 = 0.4.  So the number of mole of water = 2* 0.4 = 0.8. We already calculate its molar mass earlier.  So mass of water = molar mass * number of moles = 18 * 0.8 = 14.4

You might be interested in
Determine the limiting reactant (lr) and the mass (in g) of nitrogen that can be formed from 50.0 g n2o4 and 45.0 g n2h4. some p
Licemer1 [7]
                                                   N2O4(l) + 2 N2H4(l) → 3 N2(g) + 4 H2O(g)
1) to calculate the limiting reactant you need to pass grams to moles.
<span> moles is calculated by dividing mass by molar mass
</span>
mass of N2O4: 50.0 g 
molar mass of <span>N2O4 = 92.02 g/mol
</span><span>molar mass of N2H4 = 32.05 g/mol.
</span>mass of N2H4:45.0 g

moles N2O4=50.0/92.02 g/mol= 0,54 mol of N2O4
moles N2H4= 45/32.05 g/mol= 1,40 mol of <span><span>N2H4

</span> 2)</span>
By looking at the balanced equation, you can see that 1 mol of N2O4 needs 2 moles of N2H4 to fully react . So to react  0,54 moles of N2O4, you need 2x0,54 moles of <span>N2H4 moles
</span><span>N2H4 needed = 1,08 moles.
You have more that 1,08 moles </span><span>N2H4, so this means the limiting reagent is not N2H4, it's </span>N2O4. The molecule that has molecules that are left is never the limiting reactant.

3) 1 mol of N2O4 reacting, will produce 3 mol of N2 (look at the equation)
There are 0,54 mol of N2O4 available to react, so how many moles will produce of N2?
1 mol N2O4------------3 mol of N2
0,54 mol N2O4--------x
x=1,62 mol of N2

4) the only thing left to do is convert the moles obtained, to grams.
We use the same formula as before, moles equal to mass divided by molar mass.
moles= \frac{grams}{molar mass}             (molar mass of N2= 28)
1,62 mol of N2= mass/ 28
mass of N2= 45,36 grams

4 0
3 years ago
An atom can act as a tiny magnet due to the spinning motion of charged particles called neutrons. Please select the best answer
Tatiana [17]
Falso porque los neutrones no tienen carga
7 0
3 years ago
Whats the molar mass of potassium nitride
Lyrx [107]
<span>The answer is
101.1032 g/mol</span>
6 0
3 years ago
Ideal He gas expanded at constant pressure of 3 atm until its volume was increased from 9 liters to 15 liters. During this proce
kkurt [141]

Explanation:

The given data is as follows.

             P = 3 atm

                = 3 atm \times \frac{1.01325 \times 10^{5} Pa}{1 atm}  

                 = 3.03975 \times 10^{5} Pa

    V_{1} = 9 L = 9 \times 10^{-3} m^{3}    (as 1 L = 0.001 m^{3}),  

        V_{2} = 15 L = 15 \times 10^{-3} m^{3}

            Heat energy = 800 J

As relation between work, pressure and change in volume is as follows.

                  W = P \times \Delta V

or,                W = P \times (V_{2} - V_{1})

Therefore, putting the given values into the above formula as follows.

                  W = P \times (V_{2} - V_{1})

                      = 3.03975 \times 10^{5} Pa \times (15 \times 10^{-3} m^{3} - 9 \times 10^{-3} m^{3})

                      = 1823.85 Nm

or,                   = 1823.85 J

As internal energy of the gas \Delta E is as follows.

                     \Delta E = Q - W

                                  = 800 J - 1823.85 J

                                  = -1023.85 J

Thus, we can conclude that the internal energy change of the given gas is -1023.85 J.

8 0
3 years ago
What is the ph of a 0.25 m solution of c6h5nh2 given that its kb is 1.8 x 10-6?
IrinaK [193]

The pH a 0.25 m solution of C₆H₅NH₂ is equal to 3.13.

<h3>How do we calculate pH of weak base?</h3>

pH of the weak base will be calculate by using the Henderson Hasselbalch equation as:

pH = pKb + log([HB⁺]/[B])

pKb = -log(1.8×10⁻⁶) = 5.7

Chemical reaction for C₆H₅NH₂ is:

                          C₆H₅NH₂ + H₂O → C₆H₅NH₃⁺ + OH⁻

Initial:                     0.25                           0            0

Change:                    -x                             x             x

Equilibrium:        0.25-x                           x             x

Base dissociation constant will be calculated as:
Kb = [C₆H₅NH₃⁺][OH⁻] / [C₆H₅NH₂]

Kb = x² / 0.25 - x

x is very small as compared to 0.25, so we neglect x from that term and by putting value of Kb, then the equation becomes:

1.8×10⁻⁶ = x² / 0.25

x² = (1.8×10⁻⁶)(0.25)

x = 0.67×10⁻³ M = [C₆H₅NH₃⁺]

On putting all these values on the above equation of pH, we get

pH = 5.7 + log(0.67×10⁻³/0.25)

pH = 3.13

Hence pH of the solution is 3.13.

To know more about Henderson Hasselbalch equation, visit the below link:
brainly.com/question/13651361

#SPJ4

5 0
2 years ago
Other questions:
  • A sample containing 1.20 moles of Ne gas has an initial volume of 7.50 L. What is the final volume of the gas, in liters, when e
    8·1 answer
  • Why does galium melt
    12·1 answer
  • How big is the world?
    15·2 answers
  • MODomy
    15·1 answer
  • A sample of neon effuses from a container in 77 seconds. The same amount of an unknown noble gas requires 157 seconds. Identify
    15·1 answer
  • Lithium sulfide formula?
    10·1 answer
  • How is a pure substance different from a mixture?
    13·2 answers
  • Calculate the number of molecules in 64.5 grams of Nitrogen monoxide, NO
    12·1 answer
  • A sample of gas occupies 3.00 L with 5.00 moles present. What would
    11·1 answer
  • Water is heated to boiling and water vapor (steam) is released. Chemical change or physical change?
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!