Quick answer: Exothermic reactions mean that heat has escaped the system. The answer is A. Heat is released.
The volume of a 1.86-carat diamond in cubic centimeters is 0.106 cm³
Given,
The density of a diamond is 3.513 g/cm³.
We have to find out the volume of a 1.86-carat diamond in cubic centimeters.
Convert the units of the diamond from carat to grams, we have:
(1.86 carats) x (0.200 g / 1 carat) = 0.372 g
The volume of the diamond is obtained by dividing the mass by the density, therefore using the formula, we get
v = m / d
v = 0.372 g / (3.51 g/cm³) = 0.1059 cm³
or, v = 0.106 cm³ (approx)
Therefore, the volume of a 1.86-carat diamond is approximately 0.106 cm³.
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Answer:- 1.90 atm
Solution:- It is based on combined gas law equation, PV = nRT
In this equation, P is pressure, V is volume, n is moles of gas, R is universal gas constant and T is kelvin temperature.
If we divide both sides by V then:

We know that, molarity is moles per liter. So, in the above equation we could replace
by molarity, M of the gas. The equation becomes:
P = MRT
T = 20 + 273 = 293 K
M = 
Let's plug in the values in the equation:
P = 
P = 1.90 atm
So, the pressure of the gas is 1.90 atm.
Answer:
the answer is Ahope this helps you
Answer:
52.8 g of O2.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
4Al + 3O2 —> 2Al2O3
From the balanced equation above,
4 moles of Al reacted with 3 moles of O2 to produce 2 moles of Al2O3
Next, we shall determine the number of mole of O2 needed to react with 2.2 moles of Al. This can be obtained as follow:
From the balanced equation above,
4 moles of Al reacted with 3 moles of O2.
Therefore, 2.2 moles of Al will react with = (2.2 × 3)/4 = 1.65 moles of O2.
Thus, 1.65 moles of O2 is needed for the reaction.
Finally, we shall determine the mass of O2 needed as shown below:
Mole of O2 = 1.65 moles
Molar mass of O2 = 2 × 16= 32 g/mol
Mass of O2 =?
Mole = mass/Molar mass
1.65 = mass of O2 /32
Cross multiply
Mass of O2 = 1.65 × 32
Mass of O2 = 52.8 g
Therefore, 52.8 g of O2 is needed for the reaction.