Quantitative observation have accuracy over qualitative observation as in Quantitative observation data is recorded in terms of number .
Explanation:
Qualitative observations are descriptive observations that don't involve numbers. " The freezing point of water is colder than the boiling point " is an example. Quantitative observations are numerical measurements. "The freezing point of watrr is 0 c and boiling point is 100 c" is a quantitative observation.
Answer:
produces electrical current from electricity. produces electrical current from a nonspontaneous chemical reaction.
Explanation:
An electrolytic cell converts electrical energy into chemical energy. Here, the redox reaction is spontaneous and is responsible for the production of electrical energy. The reaction at the anode is oxidation and that at the cathode is reduction. Here, the anode is positive and the cathode is the negative electrode.
Answer:
159 mg caffeine is being extracted in 60 mL dichloromethane
Explanation:
Given that:
mass of caffeine in 100 mL of water = 600 mg
Volume of the water = 100 mL
Partition co-efficient (K) = 4.6
mass of caffeine extracted = ??? (unknown)
The portion of the DCM = 60 mL
Partial co-efficient (K) = 
where; 
solubility of compound in the organic solvent and 
= solubility in aqueous water.
So; we can represent our data as:
÷ 
Since one part of the portion is A and the other part is B
A+B = 60 mL
A+B = 0.60
A= 0.60 - B
4.6=
÷ 
4.6 = 
4.6 × =
4.6 B 
= 0.6 - B
2.76 B = 0.6 - B
2.76 + B = 0.6
3.76 B = 0.6
B = 
B = 0.159 g
B = 159 mg
∴ 159 mg caffeine is being extracted from the 100 mL of water containing 600 mg of caffeine with one portion of in 60 mL dichloromethane.
Answer: The closeness, arrangement and motion of the particles in a substance change when it changes state. Materials are a store of internal energy , due to the motion of particles and the chemical bonds between them. When a substance is heated, its internal energy increases: the movement of its particles increases.
Explanation:
