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3 years ago

What amount of heat will raise the temperature of 78g liquid water from 20 C to 80 C?

Chemistry

1 answer:

DaniilM [7]3 years ago

3 0

Answer:

19656J

Explanation:

Step 1:

Data obtained from the question.

Mass (M) = 78g

Initial temperature (T1) = 20°C

Final temperature (T2) = 80°C

Change in temperature (ΔT) = T2 – T1 =

80°C – 20°C = 60°C

Specific heat capacity (C) = 4.2J/g°C

Heat (Q) =...?

Step 2:

Determination of the heat required for the reaction.

Q = MCΔT

Q = 78 x 4.2 x 60

Q = 19656J

Therefore, 19656J of heat is required.

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The half-life of 131I is 8.021 days.What fraction of a sample of 131I remains after 24.063 days

Leno4ka [110]

24.063/8.021 = 3 half lives
(1/2)^3 =1/8

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3 years ago

During which step in "Steps to Solve a Problem” should students pick a strategy to use? Step 1 Step 2 Step 3 Step 4

Feliz [49]

Answer:

Step 3

Explanation:

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1. identifying

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2. representing

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3 years ago

Read 2 more answers

The edge length of the unit cell of KCl (NaCl-like structure, FCC) is 6.28 Å. Assuming anion-cation contact along the cell edge,

Mila [183]

Answer:

1.33 Å

Explanation:

Given that the edge length , a of the KCl which forms the FCC lattice = 6.28 Å

Also,

For the FCC lattice in which the anion-cation contact along the cell edge , the ratio of the radius of the cation to that of anion is 0.731.

Thus,

$\frac {r^+}{r^-}=0.731$ .................1

Also, the sum of the radius of the cation and the anion in FCC is equal to half of the edge length.

Thus,

$r^++r^-=\frac {a}{2}$ ...................2

Given that:

$Cl^-\ (r^-) = 1.82\ \dot{A}$

To find,

$K^+\ (r^+) = ? \dot{A}$

Using 1 and 2 , we get:

$1.731\ r^+=0.731\times \frac {6.28}{2}$

<u>Size of the potassium ion = 1.33 Å</u>

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3 years ago

An isotope contains 16 protons 18 electrons and 16 neutrons. what is the identity of the isotope

jarptica [38.1K]

Answer:

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Explanation:

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3 years ago

List a few of the physical properties of buckyball

stepladder [879]

Buckyball or buckminster fullerene is the third allotrope of carbon. It contains 60 carbons which are arranged in the five and six membered rings. Buckyball is the cluster of carbon atoms which are arranged in spherical shape and it forms a hollow cage.

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Buckyball is made up of huge number of molecules but giant covalent bond is not exist.

The forces between the individual buckyballs are weak intermolecular forces.

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The substances which are made up of buckyballs is slippery in nature.

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