corrected question: A chemist adds 135mL of a 0.21M zinc nitrate solution to a reaction flask. Calculate the mass in grams of zinc nitrate the chemist has added to the flask. Round your answer to significant digits.
Answer:
5.37g
Explanation:
0.21M means ; 0.21mol/dm³
1dm³=1L , so we can say 0.21mol/L
if 0.21mol of Zinc nitrate is contained in 1L of water
x will be contained in 135mL of water
x= 0.21*135*10³/1
=0.02835moles
number of moles= mass/ molar mass
mass= number of moles *molar mas
molar mass of Zn(NO₃)₂=189.36 g/mol
mass= 0.02835 *189.36
mass=5.37g
<u>Answer:</u> The mass percent of water in the original air sample is 4.16 %
<u>Explanation:</u>
We are given:
Volume of moist air = 12.0 L
Volume of dry air = 11.50 L
Volume of water lost = (12.0 - 11.50) L = 0.50 L
Here, the percent by mass ratio will be equal to the percent by volume ratio as the number of moles is directly related to the volume.
To calculate the volume percentage of water in the air, we use the equation:

Putting values in above equation, we get:

Hence, the mass percent of water in the original air sample is 4.16 %
<u>Answer:</u> The given electronic configuration is long hand notation.
<u>Explanation:</u>
Long-hand notation of representing electronic configuration is defined as the arrangement of total number of electrons that are present in an element.
Noble-gas notation of representing electronic configuration is defined as the arrangement of valence electrons in the element. The core electrons are represented as the previous noble gas of the element that is considered.
The given electronic configuration of potassium (K): 
The above configuration has all the electrons that are contained in the nucleus of an element. Thus, this configuration is a long-hand notation.