Answer:
1.99V
Explanation:
Balanced redox reaction equation:
3CU2+(aq) + 2Al(s) ------> 3Cu(s) + 2Al3+(aq)
E°cell= E°cathode- E°anode
E°cell= 0.34-(-1.66)
E°cell= 2.0V
From Nernst equation:
E= E°cell - 0.0592/n logQ
E= 2.0 - 0.0592/6 log [3.43]/[1.63]
E= 2.0- 0.0032
E= 1.99V
Answer:
Volume of the sulfuric acid (25cm³), same mass of each metal (1g)
Explanation:
In an experiment, the CONTROL VARIABLE also known as constant is the variable that is kept unchanged for all groups in an experiment. This is done in order not to influence the outcome of the experiment.
In this case, students are trying to investigate the reactivity of four different metals. They added 1 g of each metal to 25cm³ of sulfuric acid and recorded the temperature change. Based on the explanation of control variable above, the VOLUME OF SULFURIC ACID (25cm³) and the MASS OF EACH METAL (1g) are the CONTROL VARIABLES because they are the same or unchanged in this experiment.
Answer:
1. 1568 J
2. 0 J
3. 1176 J
Explanation:
PE = mgh
(PE = Potential Energy) = (m = mass)(g = gravitational force which is 9.8)(h = height)
1. (3)(9.8)(20) = 1568 J
2. PE = (3)(9.8)(0) = 0 J
3. (5)(9.8)(24) = 1176 J
The answer to the question
Answer: Concentration of NaOH calculated will be underestimated.
Explanation:
End point is an observational point , which tells us about the completion of reaction between the titrant (solution in burette) and titre(solution in conical flask) in titration experiment.
In this case , NaOH is titrant whose concentration is unknown.
, 
, 
....(1)
According to question a chemist overshoots the end point and adds to much of NaOH solution, which means increase in the value of 
.
Then the value of 
in equation (1), will get lowered , which means that the concentration of NaOH was lower than that of the actual value. Hence underestimated concentration of NaOH.
