<h2>Answer:</h2>
The option B is correct option. Which is release of heat and/or light energy .
<h3>Explanation:</h3>
According to the definition of exothermic reaction :
<em>An exothermic reaction is a chemical reaction that releases energy by light or heat.</em>
From definition option B (release of heat and/or light energy) indicates that an exothermic reaction has taken place.
.
2K + Br2 ===> 2KBr
It's very ionic. The transfer of 2 electrons from K to Br2 is nearly as complete as it can be.
Answer: 160 g Fe2O3
Explanation: solution attached.
First convert molecules to moles using Avogadro's number then convert to mass using the relationship between moles and molar mass of Fe2O3
Answer:
Calculate the mass percent of a potassium nitrate solution when 15.0 g KNO3 is dissolved in 250 g
of water.
2. Calculate the mass percent of a sodium nitrate solution when 150.0 g NaNO3 is dissolved in 500 mL
of water. Hint: 1 mL water = 1 g water
3. Calculate the weight of table salt needed to make 670 grams of a 4.00% solution.
4. How many grams of solute are in 2,200 grams of a 7.00% solution?
5. How many grams of sodium chloride are needed to prepare 6,000 grams of a 20% solution?
Mass Percent = Grams of Solute
Grams of Solution X 100%
100%
Grams of Solute = Grams of Solution X Mass Percent
= 26.8 grams NaCl
= 670 grams X 4.00%
100%
100%
Grams of Solute = Grams of Solution X Mass Percent
= 154 grams solute
= 2,200 grams X 7.00%
100%
100%
Grams of Solute = Grams of Solution X Mass Percent
= 1,200 grams NaCl
= 6,000 grams X 20.0%
100%
Explanation:
