Based on the data given in this question, the statement that shows a correct interpretation of the chemical reactions is as follows: reaction A was exothermic and reaction B was endothermic.
<h3>What are endothermic and exothermic reactions?</h3>
Endothermic reaction is a chemical reaction that absorbs heat energy from its surroundings while exothermic reaction is a reaction that releases energy in the form of heat.
Endothermic reactions leave their surroundings cooler while exothermic reactions leave their surroundings hotter.
According to this question, the initial and final temperatures of two reactions are given as follows:
- Reaction A: 25.1°C and 30.2°C
- Reaction B: 25.1°C and 20.0°C
From the above data, reaction A was exothermic because it increased the surrounding temperature and reaction B was endothermic because it reduced the surrounding's temperature.
Learn more about endothermic and exothermic at: brainly.com/question/23184814
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Heat is needed to change solid to liquid even to gas!
Answer:
If you contact water with a gas at a certain temperature and (partial) pressure, the concentration of the gas in the water will reach an equilibrium ('saturation') according to Henry's law.
Explanation:
This means: if you increase the pressure (e.g. by keeping the vial closed), the CO2 concentration will increase. So it simply depends what concentration you need for your assay: 'CO2-saturated' water at low pressure or 'CO2-saturated' water at high pressure.
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
