Answer: Fireworks exploding is a chemical change.
Explanation: Lighting gunpowder, and making the explosion is a chemical change.
Answer:
- <em>The calculation of quantities is chemical equations is called </em><u><em>stoichiometry.</em></u>
Explanation:
In a chemical reaction, as a result of the law of conservation of mass, reactants combine in fixed proportions to form the products.
Then, a chemical reaction is characterized by cuantitative relations between the atoms and compounds, which permit to make predictions on how much product can be obtained from certain amounts of reactants or how much of each reactant you would need to obtain a desired amount of product.
<em>Stoichiometry</em> is the use of the mole coefficients of a chemical equation to state ratios and set proportions, and, so, determine the number of moles or masses of reactants and products.
Answer:
The total mass of the solution = 99.7 g
Note: The question is incomplete. The complete question is given below:
<em>A "coffee-cup" calorimetry experiment is run for the dissolution of 2.5 g of lithium nitrate placed into 97.2 mL of water. The temperature of the solution is initially at 23.5oC. After the reaction takes place, the temperature of the solution is 28.3 oC. </em>
<em>1. Using a density of 1.0 g/mL for the water added and adding in the mass of the lithium nitrate, what is the total mass of the solution and solid?</em>
Explanation:
mass = density * volume
density of water = 1.0 g/mL; volume of water = 97.2 mL
mass of water = 1.0 g/L * 97.2 mL
mass of water = 97.2 g
mass of lithium nitrate = 2.5 g
A solution is made by dissolving a solute (usually solid) in a solvent (usually a liquid). The solute in this reaction is lithium nitrate and the solvent is water.
Total mass of solution = mass of water + mass of lithium nitrate
Total mass of solution = 97.2 g + 2.5 g = 99.7 g
Therefore, total mass of the solution = 99.7 g