All categories

3 years ago

an ice cube has a mass of 25 grams. the ice cube is placed in a glass and melts. What is true about the ice cube?

1 answer:

4 0

I believe that the ice cube, being that it still has almost all of its properties, would still have a mass of 25 g after melting

You might be interested in

What is the resultant pressure if 1.7 mol of ideal gas at 273 K and 2.79 atm in a closed container of constant volume is heated

dedylja [7]

Answer: The resultant pressure is 3.22 atm

Explanation:

Gay-Lussac's Law: This law states that pressure is directly proportional to the temperature of the gas at constant volume and number of moles.

$P\propto T$ (At constant volume and number of moles)

$\frac{P_1}{T_1}=\frac{P_2}{T_2}$

where,

$P_1$ = initial pressure of gas = 2.79 atm

$P_2$ = final pressure of gas = ?

$T_1$ = initial temperature of gas = 273K

$T_2$ = final temperature of gas = 315 K

$\frac{2.79}{273}=\frac{P_2}{315}$

$P_2=3.22atm$

Thus the resultant pressure is 3.22 atm

6 0

2 years ago

How many grams of octane (C8H18) must be burned to produce 300.0g of CO2?

nika2105 [10]

Answer:

$m_{C_8H_{18}}=85.67gC_8H_{18}$

Explanation:

Hello there!

In this case, according to the given combustion reaction of octane, it is possible for us to perform the stoichiometric method in order to calculate the mass of octane that is required to consume 300.0 g of oxygen by considering the 2:25 mole ratio, and the molar masses of 114.22 g/mol and 32.00 g/mol respectively:

$m_{C_8H_{18}}=300.0gO_2*\frac{1molO_2}{32.00gO_2}*\frac{2molC_8H_{18}}{25molO_2}*\frac{114.22gC_8H_{18}}{1molC_8H_{18}} \\\\m_{C_8H_{18}}=85.67gC_8H_{18}$

Regards!

6 0

3 years ago

Why are chemists interested in studying thermochemistry? a. Heat is often absorbed during reactions.b. Heat is often released du

Wittaler [7]

Answer:

a. Heat is often absorbed during reactions.

c. Heat is often released during chemical reactions.

Explanation:

Thermochemistry -

The study of thermochemistry involve the change in the amount of heat , during any physical or chemical process , is referred to as thermodynamics .

The focus of thermochemistry is on the changing amount of energy in the form of heat , on the system with respect to the surroundings .

The process like boiling , melting , sublimation , may require energy or releases energy , and hence are studied under thermochemistry .

Hence , from the given question ,

The correct options are - a , c.

6 0

3 years ago

A mixture of helium, nitrogen and oxygen has a total pressure of 821 mmHg. The partial pressure of helium is 105 mmHg, and the p

skad [1K]

Answer:

Total partial pressure, Pt = 821 mm Hg

Partial pressure of Helium, P1 = 105 mm Hg

Partial pressure of Nitrogen, P2 = 312 mm Hg

Partial pressure of Oxygen, P3 = ? mm Hg

According to Dalton's law of Partial pressures,

Pt = P1 + P2 + P3

So, <u>P3 = 404 mm Hg</u>

4 0

2 years ago

You have a solution that is 0.02M formate (HCOO-) and 0.03M formic acid (HCOOH), which has a Ka of 1.8x10-4. What is the pH of t

lisov135 [29]

Answer:

3.6

Explanation:

Step 1: Given data

Concentration of formic acid: 0.03 M

Concentration of formate ion: 0.02 M

Acid dissociation constant (Ka): 1.8 × 10⁻⁴

Step 2: Calculate the pH

We have a buffer system formed by a weak acid (HCOOH) and its conjugate base (HCOO⁻). We can calculate the pH using the <em>Henderson-Hasselbach equation</em>.

$pH = pKa +log\frac{[base]}{[acid]} = -log 1.8 \times 10^{-4} + log \frac{0.02}{0.03} = 3.6$

6 0

3 years ago