Answer:
0.136g
Explanation:
A student dissolved 5.00 g of Co(NO3)2 in enough water to make 100. mL of stock solution. He took 4.00 mL of the stock solution and then diluted it with water to give 275. mL of a final solution. How many grams of NO3- ion are there in the final solution?

Initial mole of Co(NO3)2 

Mole of Co(NO3)2 in final solution

Mole of NO3- in final solution = 2 x Mole of Co(NO3)2

Mass of NO3- in final solution is mole x Molar mass of NO3

Answer:
B.) If sodium carbonate is added to vinegar, the reaction will absorb heat.
Explanation:
A.) is incorrect because this is not testable. Rather, it is just an opinion that cannot be proven correct or incorrect.
B.) is correct because this statement is testable. Tests need to be run to determine the accuracy of the statement.
C.) is incorrect because this statement explains something that does not need to be tested. It is an example of a physical change when one tears a piece of paper.
D.) is incorrect because this is already a true statement. It is obvious that not all reactions absorb/release heat. While tests could be run to further prove this statement true, it is already considered accurate.
Answer:
Its 1s22s22p63s23p1 ik it looks a lil goofy but i think its right
Explanation:
Answer:When a person hyperventilates they exhale more carbon dioxide than normal. As a result the carbon dioxide concentration in the blood is reduced and the bicarbonate/carbonic acid equilibrium shifts to the left. The corresponding drop in H3O+ concentration causes an increase in pH.
Explanation: