Answer:
boron
Explanation:
boron has 5 protons and carbon has 6, so if carbon lost a proton, it would become boron since each element has a unique number of protons.
Pure- table salt
Impure- vegetable oil
Answer:
a solution color becoming less intense due to dilution- is not an evidence of a chemical reaction
bubbles (gas formation) - evidence of a chemical reaction
explosion or fire - evidence of a chemical reaction
changes in color- evidence of a chemical reaction
precipitation- evidence of a chemical reaction
changes in temperature - evidence of a chemical reaction
a solid liquifying - is not an evidence of a chemical reaction
solution colors mixing - is not an evidence of a chemical reaction
Explanation:
A chemical change is not easily reversible and yields new substances. It is often accompanied by a loss or gain of heat.
In the answer section, i have shown some evidences that lead us to conclude that a chemical reaction has taken place. The occurrence of a chemical change often goes with the formation of new substances as earlier stated and any of these signs may accompany the process.
For instance, when a metal is dropped in dilute acid solution, bubble of hydrogen gas indicates that a chemical reaction has taken place.
When an acid is neutralized by a base, that means moles of H+ = moles of OH-
moles of H+ = 0.5 M * 0.025 L HCl = 0.0125 moles H+
moles of OH- should be equal to 0.0125 moles, so
0.0125 moles = (x) * 0.025 L NaOH
x is the concentration of NaOH, which we want to find.
x = 0.5 M
The correct answer is C) 0.5 M.
