Answer:

Explanation:
We are asked to find the pressure of a gas given a change in volume. Since the temperature remains constant, we are only concerned with volume and pressure. We will use Boyle's Law, which states the volume is inversely proportional to the pressure. The formula for this law is:

Initially, the oxygen gas occupies a volume of 18.7 liters at a pressure of 1.19 atmospheres.

The gas expands to a volume of 29.4 liters, but the pressure is unknown.

We are solving for the new pressure, so we must isolate the variable
. It is being multiplied by 29.4 liters. The inverse operation of multiplication is division. Divide both sides of the equation by 29.4 L.


The units of liters cancel.



The original measurements all have 3 significant figures, so our answer must have the same. For the number we calculated, that is the thousandth place. The 9 in the ten-thousandth place to the right of this place tells us to round the 6 up to a 7.

The pressure of the gas sample is approximately <u>0.757 atmospheres.</u>
Answer:
The reaction between amines and carboxylic acids to form amides is biologically important. It is through this reaction that amino acids (molecules containing both amine and carboxylic acid substituents) link together in a polymer to form proteins.
Answer:
<h3>The answer is 3.44 g/cm³</h3>
Explanation:
The density of a substance can be found by using the formula

From the question
mass = 17.2 g
volume = 5 cm³
We have

We have the final answer as
<h3>3.44 g/cm³</h3>
Hope this helps you
A compound is a substance composed of 2 or more chemical elements.
The model does not represent a compound because it shows two atoms of the same element combined. To be a compound the model would need to contain atoms of different element, represented by different colored balls. Therefore, the picture does not represent a compound. :)