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aalyn [17]
3 years ago
7

In a chemical equation, what do the coefficients indicate?

Chemistry
2 answers:
just olya [345]3 years ago
8 0

The answer is D. a number preceding an elemental or molecular symbol.

example - <u>2</u>H2 + O2  -> <u>2</u>H2O

The underlined is the coefficient.

Mekhanik [1.2K]3 years ago
6 0
In a chemical equation coefficients indicate the number of molecules/atoms involved in the reaction.
You might be interested in
If an ice cube weighing 25.0 g with an initial
riadik2000 [5.3K]

Answer:

11

∘

C

Explanation:

As far as solving this problem goes, it is very important that you do not forget to account for the phase change underwent by the solid water at

0

∘

C

to liquid at

0

∘

C

.

The heat needed to melt the solid at its melting point will come from the warmer water sample. This means that you have

q

1

+

q

2

=

−

q

3

(

1

)

, where

q

1

- the heat absorbed by the solid at

0

∘

C

q

2

- the heat absorbed by the liquid at

0

∘

C

q

3

- the heat lost by the warmer water sample

The two equations that you will use are

q

=

m

⋅

c

⋅

Δ

T

, where

q

- heat absorbed/lost

m

- the mass of the sample

c

- the specific heat of water, equal to

4.18

J

g

∘

C

Δ

T

- the change in temperature, defined as final temperature minus initial temperature

and

q

=

n

⋅

Δ

H

fus

, where

q

- heat absorbed

n

- the number of moles of water

Δ

H

fus

- the molar heat of fusion of water, equal to

6.01 kJ/mol

Use water's molar mass to find how many moles of water you have in the

100.0-g

sample

100.0

g

⋅

1 mole H

2

O

18.015

g

=

5.551 moles H

2

O

So, how much heat is needed to allow the sample to go from solid at

0

∘

C

to liquid at

0

∘

C

?

q

1

=

5.551

moles

⋅

6.01

kJ

mole

=

33.36 kJ

This means that equation

(

1

)

becomes

33.36 kJ

+

q

2

=

−

q

3

The minus sign for

q

3

is used because heat lost carries a negative sign.

So, if

T

f

is the final temperature of the water, you can say that

33.36 kJ

+

m

sample

⋅

c

⋅

Δ

T

sample

=

−

m

water

⋅

c

⋅

Δ

T

water

More specifically, you have

33.36 kJ

+

100.0

g

⋅

4.18

J

g

∘

C

⋅

(

T

f

−

0

)

∘

C

=

−

650

g

⋅

4.18

J

g

∘

C

⋅

(

T

f

−

25

)

∘

C

33.36 kJ

+

418 J

⋅

(

T

f

−

0

)

=

−

2717 J

⋅

(

T

f

−

25

)

Convert the joules to kilojoules to get

33.36

kJ

+

0.418

kJ

⋅

T

f

=

−

2.717

kJ

⋅

(

T

f

−

25

)

This is equivalent to

0.418

⋅

T

f

+

2.717

⋅

T

f

=

67.925

−

33.36

T

f

=

34.565

0.418

+

2.717

=

11.026

∘

C

Rounded to two sig figs, the number of sig figs you have for the mass of warmer water, the answer will be

T

f

=

11

∘

C

Explanation:

3 0
2 years ago
Answer this i will mark brainliest and don't steal points im gonna report you ​
Nuetrik [128]
The answer is for this is A
3 0
2 years ago
Read 2 more answers
In what situation do we use a volumetric flask, conical flask, pipette and graduated cylinder? Explain your answer from accuracy
Ad libitum [116K]
A volumetric flask is used to contain a predetermined volume of substance and only measures that volume, for example 250 ml.
Conical flasks can be used to measure the volume of substances but the accuracy they provide is usually up to 10ml. Conical flasks are used in titrations, reactions where the liquid may boil, and reactions which involve stirring. 
Pippettes are of two types, volumetric and graduated. Pippettes are used where high accuracy is required and volumetric pippettes come in as little as 1 ml. Pippettes are usually used in titrations.
Graduated cylinders come in a wide variety of sizes and their accuracy can be down to as much as 1 ml. They are used to contain liquids.
3 0
3 years ago
Write the molecular formula for the compound that exhibits a molecular ion at M+ = 112.0499. Assume that C, H, N, and O might be
navik [9.2K]

Answer:

C₆H₁₀NO

Explanation:

In order to arrive at a molecular formula we have to make some assumptions and they are

Assuming there is one ( 1 ) N and one ( 1 ) O that is present in the said molecule

Total mass =   29.998

next step: subtract the total mass from 112.0499 = 82.501

next : assume the presence of 6 carbon atoms in said molecule

Total mass =  6 * 12 = 72

Mass of Hydrogens = 82.501 - 72 = 10.501

∴ number of hydrogens = 10.501 / 1.0078  ≈ 10

Hence Total mass = 29.998 + 82.501  ≈ 112.0499

Finally Molecular formula = C₆H₁₀NO

3 0
3 years ago
By what mechanism does cyclohexanol react when treated in concentrated sulfuric acid/phosphoric acid and what compound results?
slava [35]

Answer:

The mechanism is E1 and the product is cyclohexene

Explanation:

Attached to this answer is an image of the reaction mechanism of the reaction between cyclohexanol and concentrated sulfuric acid/phosphoric acid. The acid (H3O^+) acts as catalyst.

We can see that the first step in the mechanism is the protonation of the -OH group of the alcohol. This is followed by loss of water molecule which is a good leaving group.

The water now acts as a Lewis base by abstracting a proton from the substrate, forming cyclohexene and regenerating the acid catalyst.

6 0
3 years ago
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