Which of the following is true of the gas constant, R?

If 420 joules of heat energy is added to 25 grams of water at 25 degrees celcius, what will be the final temperature of the wate

natka813 [3]

Answer:

T2 = 29°C

Explanation:

Given data:

Heat added = 420 j

Mass of water = 25 g

Initial temperature = 25°C

Final temperature = ?

Solution;

Specific heat capacity:

It is the amount of heat required to raise the temperature of one gram of substance by one degree.

Specific heat capacity of water = 4.18 j/g.°C

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

Now we will put the values.

420 j = 25 g ×4.18 j/g.°C × (Final temperature - initial temperature)

420 j = 25 g ×4.18 j/g.°C × (T2 - 25°C)

420 j = 104.5 j/°C × (T2 - 25°C)

420 j /104.5 j/°C = T2 - 25°C

4°C + 25°C = T2

T2 = 29°C

4 0

4 years ago

Rank the following compounds in order of increasing solubility in water. Items (4 items) (Drag and drop into the appropriate are

charle [14.2K]

Answer:

CaO < BaO < KCl <KI

Explanation:

Let us remember that the solubility of an ionic substance in water depends on the magnitude of the lattice energy and the hydration energy. If the hydration energy is equal to or is greater than the lattice energy, the substance dissolves in water.

However, the lattice energy depends on the size of the ions. The smaller the ions in the ionic compound, the higher the lattice energy and the lesser the solubility of the ionic compound.

KI has the least lattice energy and the highest solubility in water while CaO has the highest lattice energy and the least solubility in water.

6 0

3 years ago

Yasir wants to determine if there is a relationship between room color and sleep. Based on his research, Yasir makes an educated

tia_tia [17]

Answer:

B). An Experiment that tests the hypothesis.

Explanation:

The element that is missing from Yasir's scientific investigation is 'an experiment which tests a hypothesis.' His experiment does not provide a verifiable statement revealing his proposition or prediction regarding the possible outcome of the experiment which could be verified by using a research or investigation. He rather tests his proposition indirectly by asking 'which color they like better' and using it to make an educated guess. Thus, <u>option B</u> is the correct answer.

8 0

4 years ago

An air-filled balloon has a volume of 225 L at 0.940 atm and 25 °C. Soon after, the pressure changes to 0.990 atm and the temper

lorasvet [3.4K]

Answer:

The right choice is V₂ = 195.7 L

Explanation:

We can use the general law of ideal gas: PV = nRT.

where, P is the pressure of the gas in atm.

V: is the volume of the gas in L.

n: is the no. of moles of the gas in mol.

R: is the general gas constant,

T: is the temperature of the gas in K.

If n is constant, and have different values of P, V and T:

(P₁*V₁) / T₁ = (P₂ * V₂) / T₂

Knowing that:

V₁ = 225 L , P₁ = 0.940 atm

T₁ = 25 °C + 273 = 298 K

V₂ = ??? L, P₂ = 0.990 atm

T₂ = 0 °C + 273 = 273 K

applying in the above equation

(P ₁* V₁) / T₁ = (P₂ * V₂) / T₂

(0.940 atm * 225 L) / 298 K= (0.990 atm * V₂) / 273 K

V₂ = (0.940 atm * 225 L * 273 K) / (298 K * 0.990 atm)

V₂ = 195.7 L

So, the right choice is:

V₂ = 195.7 L

7 0

3 years ago

Plastic, rocks, and steel are all matter. They are made of tiny particles that can’t be broken down into smaller pieces. These p

andrew11 [14]

Answer:

These particles are all called atoms.

Explanation:

Atoms are referred to as the building blocks of all matter. This is because atoms are the smallest pieces that all matter can be broken down into, whether the matter is in a solid, liquid or gaseous state. Atoms combine to form bigger particles called molecules. These molecules are what forms the objects in our surrounding environment. Atoms are comprised of three particles: electrons which have a negative charge, protons which have a positive charge and neutrons which have no charge.

3 0

3 years ago

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