Percent Yield

One of the topics we learned in Chemistry this term was about percent yield. Percent yield was about how much we made, using the amount that we could make, and was formed with the relationship of theoretical yield and actual yield. Theoretical yield was the amount that we expected to get, and the actual yield was the amount that we actually get. Therefore, to calculate percent yield, we would take the actual yield divided by theoretical yield and times everything by 100. Noted that the actual yield will always be smaller than theoretical yield, based on the definitions of the two words, this idea makes senses; some amount of something that we expected to get could be greater or smaller than the actual amount, however, talking in terms of producing product, for example, rice, farmers would most likely predicted that their farms would give them a very high quantity.

To get more in depth about percent yield as well to understand better about this topic in particular, we also did a lab on percent yield. We made smore using some ingredients/reactants that we were given. It was a very enjoyable lab because at the end, each of us got to taste our smore! For more details of the lap, check out my lab report (link below) that I worked with my other two friends. 




Unit 1 Exam

1.) What is the difference between a qualitative and quantitative observation?

Qualitative observation is where we only need the meaning, concepts, or the characteristic of what we are observing,

Quantitative observation is where need mathematics, numbers, statistic..etc, in our observation.

For example: qualitative observation  → The water is very cold.

For example: quantitative observation → The water is approximately 2 degree Celsius.

2.) Ellie realizes that all of her plants die within a few months of her care.  She wants to check the effectiveness of fertilizer. She gives 6 plants in group A fertilizer, and 6 plants in group B no fertilizer.  She then measures the growth of the plants to see if the fertilizer helps them grow.

What is the control group? 

6 plants in group B with no fertilizer  

What is the experimental group?

6 plants in group A with fertilizer

What is the independent variable?

the effectiveness of fertilizer 

What is the dependent variable?

growth of plants

3.) What is the difference between precise and accurate?

Precision is (when you’re doing an experiment) how do you get the same answer when you’re using the same method, while accuracy is how close you are in getting to the correct answer.

4.) Convert the following numbers to scientific notation:

  1. ) 0.00432 → 4.32*10^-3 b.) 34500 → 3.45*10^4

5.)  If you measured the area of something that had a length of 5.0m and a width of 3.456m, how many significant figures would be in your answer?

The answer should have only 1 significant figure and with the rounded value because the fewest decimal place in the problem has only one sig fig

For example = 5.0*3.456 = 17.2800   but since the fewest decimal place in the problem has only one sig fig, the answer should be 17.3

6.) How many significant figures are in each of the following measurements?

  1. 3400 cm → 2 sig figs
  2. 0.00043200 L → 5 sig figs

C = K- 273      

7.)  If a thermometer reads  340C, what would the temperature be in Kelvin?

C = K-273 → K = C+273 = 34+273

= 307 Kelvin