Get premium membership and access questions with answers, video lessons as well as revision papers.

50cm³ of 10% glucose solution was boiled and allowed to cool. The solution was then poured into a vacuum flask and about 5cm³ of groundnut oil...

      

50cm³ of 10% glucose solution was boiled and allowed to cool. The solution was then poured into a vacuum flask and about
5cm³ of groundnut oil added to it. 10% yeast solution was introduced into the glucose solution using a pipette. A
thermometer was placed in the flask and supported with a cotton wool plug. A second flask was set up as above, but
containing cooled boiled water instead of 10% glucose solution. The temperature of each flask was recorded at the
beginning and thereafter at hourly intervals for several hours.
a) Why was a vacuum flask used in this experiment?
b) What was the purpose of the second flask?
c) Write a word equation to summarize the reaction that took place in the first flask.
d) Why was groundnut oil added to the flask?
e) Why was it necessary to boil the glucose and the water before they were poured into the flask?

  

Answers


sharon
a) To avoid loss of any heat generated in the flask;
b) Control set up;
c) Glucose -------->(yeast> alcohol + carbon (IV) oxide + Energy;
d) To avoid infiltration of oxygen;
e) To expel any oxygen dissolved in the glucose;
sharon kalunda answered the question on May 24, 2019 at 07:44


Next: Read the Oral Narrative below and answer the questions that follow.
Previous: Three sterilized petri dishes I, II and III were half filled with sterilized nutrient agar jelly and then treated as shown below. The petri dishes were...

View More Biology Questions and Answers | Return to Questions Index


Learn High School English on YouTube

Related Questions