In a physical change the appearance or form of the matter changes but the kind of matter in the substance does not. However in a chemical change, the kind of matter changes and at least one new substance with new properties is formed. The distinction between physical and chemical change is not clear cut.
Answer:
- Break down a problem into smaller units or sub-problems.
- Reverse engineering, or taking something apart so as to evaluate and provide solutions.
Explanation:
For the first one, if you are a computer engineer for example, it is hard to troubleshoot a whole program but if you write small stand alone sections, you can easily troubleshoot the smaller section.
The pH of the sodium hydroxide (NaOH) solution at the given concentration of 0.000519 M is determined as 10.72.
<h3>What is pH of solution?</h3>
The pH of a solution is defined as the logarithm of the reciprocal of the hydrogen ion concentration [H+] of the given solution.
Concentration of the basic solution, [OH⁻] = 0.000519
pOH = -log[OH⁻]
pOH = -log[0.000519]
pOH = 3.28
<h3>pH of the solution</h3>
pH + pOH = 14
pH = 14 - pOH
pH = 14 - 3.28
pH = 10.72
Thus, the pH of the sodium hydroxide (NaOH) solution at the given concentration of 0.000519 M is determined as 10.72.
Learn more about pH here: brainly.com/question/26424076
A chemical change occurs when the identity of a substance is changed. Silver tarnishing is a chemical change because silver and sulfur react to form a new substance, silver sulfide. In the other examples, the substances have not changed their identity and only physical changes have occurred. the correct answer is D
Answer:
THE SPECIFIC HEAT OF THE METAL IS 0.8983 J/g °C
Explanation:
In solving the problem, we have to understand that:
Heat lost by the metal = Heat gained by the water in the bomb calorimeter
First is to calculate the heat evolved from the reaction
Heat = mass * specific heat * change in temperature
Mass of water = 50 g
specific heat of water = 4.184 J/g °C
Change in temperature = 23 - 21 = 2 °C
So therefore,
Heat = 50 * 4.184 * 2
Heat = 418.4 J
Next is to solve for the specific heat of the metal;
Heat lost by the metal is the same as the heat gained by water
Heat = mass * specific heat of metal * change in temperature
Change in temperature = 39.4 °C - 23 °C = 16.4 °C
418.4 = 28.4 * C * 16.4
C = 418.4 / 28.4 * 16.4
C = 418.4 / 465.76
C = 0.8983 J/ g °C
The specific heat of the metal is hence 0.8983 J/g °C
