Answer: D) 1.00 g
Explanation:
According to the Avogadro's law, the volume of gas is directly proportional to the number of moles of gas at same pressure and temperature. That means,

or,

where,
= initial volume of gas = 2.00 L
= final volume of gas = 3.00 L
= initial moles of gas =
= final moles of gas = ?
Now we put all the given values in this formula, we get


Mass of helium =
Thus mass of helium added = (3.00-2.00) g = 1.00 g
<span>There
are a number of ways to express concentration of a solution. This includes
molarity. Molarity is expressed as the number of moles of solute per volume of
the solution. So, we calculate as follows:
Molarity = 15.9 g BaCl2 ( 1 mol / 208.23 g ) / .375 L = 0.204 mol / L</span>
Answer:
Option D - It tells which compounds will dissolve in water.
Explanation:
It is used to predict whether or not a given ionic compound is soluble.
Answer:
A biology investigation usually starts with an observation—that is, something that catches the biologist’s attention. For instance, a cancer biologist might notice that a certain kind of cancer can't be treated with chemotherapy and wonder why this is the case. A marine ecologist, seeing that the coral reefs of her field sites are bleaching—turning white—might set out to understand why.
How do biologists follow up on these observations? How can you follow up on your own observations of the natural world? In this article, we’ll walk through the scientific method, a logical problem-solving approach used by biologists and many other scientists.
Explanation:
An average quality lawn captures 4 times the carbon output of a typical gasoline-powered mower.