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3 years ago

What is the specific heat of the following materials:

Chemistry

1 answer:

Sphinxa [80]3 years ago

7 0

Answer:the sun

Explanation:leqjs

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A balloon contains 2.0 L of air at 101.5 kPa. You squeeze the balloon to a volume of .75 L. What is the pressure of air on the i

Nataly_w [17]

You would use the formula for Boyle's Law:

(P1) (V1) = (P2) (V2)

(101.5) (2.0) = (P2?) (.75)

*P2 = 270kPa (You're allowed 2 significant figures)

P = Pressure

V = Volume

3 0

3 years ago

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Which of an atom's electrons are inrolved in chemical reactions?

Scrat [10]

Answer:

Electrons at the outermost energy level of an atom are called valence electrons. They determine many of the properties of an element. That's because these electrons are involved in chemical reactions with other atoms. Shared electrons bind atoms together to form chemical compounds.

Explanation:

8 0

3 years ago

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Which concept can explain the acidic character of Carbon dioxide?

Mamont248 [21]

Answer:

The concept of lewis acids and bases can explain the acidic nature of CO2. A lewis acid is a compound which can accept an electron pair whereas a lewis base is a compound which can donate an electron pair. CO2 acts as a lewis acid.

5 0

2 years ago

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Potassium nitrate has a lattice energy of -163.8 kcal/mol and a heat of hydration of -155.5 kcal/mol.

Brut [27]

Answer:

293.99 g

0.293 Kg

Explanation:

Given data:

Lattice energy of Potassium nitrate (KNO3) = -163.8 kcal/mol

Heat of hydration of KNO3 = -155.5 kcal/mol

Heat to absorb by KNO3 = 101kJ

To find:

Mass of KNO3 to dissolve in water = ?

Solution:

Heat of solution = Hydration energy - Lattice energy

= -155.5 -(-163.8)

= 8.3 kcal/mol

We already know,

1 kcal/mol = 4.184 kJ/mole

Therefore,

= 4.184 kJ/mol x 8.3 kcal/mol

= 34.73 kJ/mol

Now, 34.73 kJ of heat is absorbed when 1 mole of KNO3 is dissolved in water.

For 101 kJ of heat would be

= 101/34.73

= 2.908 moles of KNO3

Molar mass of KNO3 = 101.1 g/mole

Mass of KNO3 = Molar mass x moles

= 101.1 g/mole x 2.908

= 293.99 g

= 0.293 kg

293.99 g potassium nitrate has to dissolve in water to absorb 101 kJ of heat.

4 0

3 years ago

In the early 1960s, radioactive strontium-90 was released during atmospheric testing of nuclear weapons and got into the bones o

Advocard [28]

Answer:

52.54 %

Explanation:

Half life = 29 years

$t_{1/2}=\frac {ln\ 2}{k}$

Where, k is rate constant

So,

$k=\frac {ln\ 2}{t_{1/2}}$

$k=\frac {ln\ 2}{29.0}\ {years}^{-1}$

The rate constant, k = 0.023902 hour⁻¹

From 1964 to 1991:

Time = 27 years

Using integrated rate law for first order kinetics as:

$[A_t]=[A_0]e^{-kt}$

Where,

$[A_t]$ is the concentration at time t

$[A_0]$ is the initial concentration

So,

$\frac {[A_t]}{[A_0]}=e^{-0.023902\times 27}$

$\frac {[A_t]}{[A_0]}=0.5245$

The strontium-90 remains in the bone = 52.54 %

5 0

3 years ago