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3 years ago

If 20.0 grams of Al is placed into a solution containg

Chemistry

1 answer:

meriva3 years ago

5 0

Answer:

m H2(g) = 2.241 g H2(g)

Explanation:

2Al(s) + 3H2SO4(aq) → Al2(SO4)3(aq) + 3 H2(g)

limit reagent:

∴ Mw Al = 26.982 g/mol

∴ Mw H2SO4 = 98.0785 g/mol

⇒ n Al = (20 g Al)×(mol/26.982 g) = 0.7412 mol Al

⇒ n H2SO4 = ( 115 g H2SO4 )×(mol/98.0785 g) = 1.173 mol H2SO4

⇒ n H2 = (0.7412 mol Al)×(3 mol H2/ 2 mol Al) = 1.112 mol H2

∴ Mw H2 = 2.016 g/mol

⇒ g H2 = (1.112 mol H2)×(2.016 g/mol) = 2.241 g H2

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25.0 g sample of compound A is mixed with a 40.0 g sample of compound B. a chemical reaction occurs. Once the reaction is comple

artcher [175]

Answer:

Explanation:

Mass of compound A = 25g

Mass of compound B = 40g

Mass of final mixture = 55g

What happens to the missing mass?

According to the law of conservation of mass, in chemical reaction, matter is transformed from one form to another but cannot be created nor destroyed.

We expect the final mass of the mixture and that of the reacting compounds to be the same but the opposite is the case.

There is a mass loss which typifies most chemical reaction.

The reason for this is that some of the masses must have been lost by the production of gaseous species which are unaccounted for.

The missing mass:

Total mass expected = mass of A + mass of B = 25 + 40 = 65g

Missing mass = expected mass - mass of final mixture = 65 - 55 = 10g

4 0

2 years ago

A substance decays so that the amount a of the substance left at time t is given by: a = a0 ∙ (0.8)t where a0 is the original am

Zolol [24]

The half-life of the substance is 3.106 years.

<h3>What is the formula for exponential decay?</h3>

The exponential decline, which is a rapid reduction over time, can be calculated with the use of the exponential decay formula.
The exponential decay formula is used to determine population decay, half-life, radioactivity decay, and other phenomena.
The general form is F(x) = a.

Here,

a = the initial amount of substance

1-r is the decay rate

x = time span

The equation is given in its correct form as follows:

a = $a_{0}$ × $(0.8)^{t}$

As this is an exponential decay of a first order reaction, t is an exponent of 0.8.

Now let's figure out the half life. Since the amount left is half of the initial amount at time t, that is when:

a = 0.5 a0

<h3>Substituting this into the equation:</h3>

0.5 $a_{0}$ = $a_{0}$ × $(0.8)^{t}$

0.5 = $(0.8)^{t}$

taking log on both sides

t log 0.8 = log 0.5

t = log 0.5/log 0.8

t = 3.106 years

The half-life of the substance is 3.106 years.

To learn more about exponential decay formula visit:

brainly.com/question/28172854

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4 0

1 year ago

How does La Niña affect the climate of the Pacific Ocean?

Shkiper50 [21]

2. the cold water sinks deeper into the ocean

6 0

3 years ago

Propane camping stoves produce heat by the combustion of gaseous propane (C3H8). Balance the skeletal equation for the combustio

Darina [25.2K]

Easy (:

C₃H₈ (g) + O₂ (g) ---> CO₂ (g) + H₂O

1 C₃H₈ (g) + 5 O₂ (g) ---> 3 CO₂ (g) + 4 H₂O

With this there is the same amount of elements on each side (You take the larger number in front and multiply it by whats after it. So you have 3 C, 8 H, and 10 O on one side, and then the next mirrors is with 3 C, 8 H, and 10 O.

3 0

2 years ago

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Which of the following is necessary for two organisms to be considered as coexisting in a mutualistic relationship?

Mrac [35]

D: Both organisms benefit

6 0

3 years ago

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