Answer:
The correct answer is - 2770000 cm.
Explanation:
1 kilometer = 1000 meter
1 meter = 100 centimeter
1 kilometer = 100*1000 cm
1 km = 100000 cm.
then,
27.7 kilometers = 2.77 × 10^6 centimeters
So, 27.7 kilometers = 27.7 × 100000
= 2.77 × 106 or 2770000 centimeters.
To find this, we will use this formula:
Molar mass of element
------------------------------------ x 100
Molar mass of compound
So, first lets calculate the mass of the compound as a whole. We use the atomic masses on the periodic table to determine this.
Ca: 40.078 g/mol
N2 (there is two nitrogens): 28.014 g/mol
O6 (there are six nitrogens: 3 times 2): 95.994 g/mol
When we add all of those numbers up together, we get 164.086. That is the molar mass for the whole compound. However, we are trying to figure out what percent of the compound oxygen makes up. From the molar mass, we know that 95.994 of the 164.086 is oxygen. Lets plug those numbers into our equation!
95.994
-----------
164.086
When we divide those two numbers, we get .585. When we multiply that by 100, we get 58.5.
So, the percent compostition of oxygen in Ca(NO3)2, or, calcium nitrate, is 58.5%.
Answer:
Yes
Explanation: Had a question like this and I said yes and got it right
Answer: Option (b) is the correct answer.
Explanation:
Buffere is defined as the solution to whom when an acid or base is added then it resists any in change in pH of the solution.
This is because a buffer has the ability to not get affected by the addition of small amounts of an acid or a base. So, basically it keeps the concentration of both hydrogen ions and hydroxides equal. As a result, it helps in maintaining the pH of the solution.
And, the capacity of a buffer solution to resist the change is known as buffer capacity.
Thus, we can conclude that buffering capacity refers to the extent to which a buffer solution can counteract the effect of added acid or base.
