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3 years ago

Which of the following will result in a chemical change?

Chemistry

2 answers:

Alinara [238K]3 years ago

5 0

C burning coal in a furnace

Galina-37 [17]3 years ago

3 0

The answer is C. I just finished the test.

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if a gas sample in a balloon occupies 1.5 L at atmospheric pressure, what would be the pressure (in mmHg) if the volume was redu

Nata [24]

Answer:

1425 mmHg.

Explanation:

The following data were obtained from the question:

Initial volume (V1) = 1.5 L

Initial pressure (P1) = 1 atm

Final volume (V2) = 0.8 L

Final pressure (P2) =?

Next, we shall determine the final pressure of the gas by using the Boyle's law equation as follow:

P1V1 = P2V2

1 × 1.5 = P2 × 0.8

1.5 = P2 × 0.8

Divide both side by 0.8

P2 = 1.5/0.8

P2 = 1.875 atm

Finally, we shall convert 1.875 atm to mmHg.

This can be obtained as follow:

1 atm = 760 mmHg

Therefore,

1.875 atm = 1.875 × 760 = 1425 mmHg.

Therefore, the new pressure of the gas is 1425 mmHg.

3 0

3 years ago

A) State the Law of Conservation of Matter.

Mariulka [41]

Answer:

matter can either be created nor destroyed but can be transmitted fromone state to another state

4 0

2 years ago

Why are plastic building blocks good for building molecules

9966 [12]

Plastic building blocks are good for building molecules because of some useful properties which they possess. For instance, plastic are flexible, they can be easily manipulated and can be made into any shape, size and combination. They can also be produced using different colors. Because of these features, they can be used to build and to explain how molecules behave.

5 0

3 years ago

Read 2 more answers

Determine the missing species:

Galina-37 [17]

Answer: 4. $^{0}_{-1}\textrm{e}$ and $^{0}_{1}\textrm{e}$

Explanation:

a) The given reaction is $^{41}_{20}\textrm{Ca}+^{x}_{y}\textrm{X}\rightarrow ^{41}_{19}\textrm {K}$

As the mass on both reactant and product side must be equal:

$41+x=41$

$x=0$

As the atomic number on both reactant and product side must be equal:

$20+y=19$

$y=-1$

$^{41}_{20}\textrm{Ca}+^{0}_{-1}\textrm{e}\rightarrow ^{41}_{19}\textrm {K}$

b) $^{15}_{8}\textrm{O}\rightarrow ^{15}_{7}\textrm{N}+^{x}_{y}\textrm{X}$

Total mass on reactant side = total mass on product side

15 =15 + x

x = 0

Total atomic number on reactant side = total atomic number on product side

8 = 7 + y

y = 1

$^{15}_{8}\textrm{O}\rightarrow ^{15}_{7}\textrm{N}+^{0}_{1}\textrm{e}$

5 0

2 years ago

What is the concentration (in M) of a sample of the unknown dye with an absorbance of 0.25 at 542 nm?

Sladkaya [172]

Answer:

see explanation below

Explanation:

Question is incomplete, so in picture 1, you have a sample of this question with the missing data.

Now, in general terms, the absorbance of a substance can be calculated using the beer's law which is the following:

A = εlc

Where:

ε: molar absortivity

l: distance of the light in solution

c: concentration of solution

However, in this case, we have a plot line and a equation for this plot, so all we have to do is replace the given data into the equation and solve for x, which is the concentration.

the equation according to the plot is:

A = 15200c - 0.018

So solving for C for an absorbance of 0.25 is:

0.25 = 15200c - 0.018

0.25 + 0.018 = 15200c

0.268 = 15200c

c = 0.268/15200

c = 1.76x10⁻⁵ M

5 0

2 years ago