Complete question
A student measures the mass of a 1.0 kg standard bar. He obtains measurements of 0.77 kg, 0.78 kg, and 0.79 kg. Which describes his measurements
a)precise but not accurate
b)accurate but not precise
c)neither precise nor accurate
d)both precise and accurate
Answer:
The measurement is precise but not accurate
Explanation:
A measurement can either be precise or accurate.
- A Precise measurement describes how close the measured values are to each other.
- An accurate measurement describes how close a measured value is to the true value.
In this question, the measured values (0.77 kg, 0.78 kg and 0.79 kg) are far from the true value (1.0 kg), therefore the measurement is not accurate.
However, the measured values (0.77 kg, 0.78 kg and 0.79 kg) are close to each other, therefore the measurement is precise.
Therefore the correct option is 'a' the measurement is precise but not accurate
Answer : The products of this reaction are, 
and 
Explanation :
First we have to write the balanced chemical reaction.
In this reaction, 1 mole of copper nitrate react with the 2 moles of sodium hydroxide to give 1 mole of copper hydroxide and 2 moles of sodium nitrate.
This reaction is a double displacement reaction.
Double displacement reaction : A type of reaction in which a positive cation and a negative anion of two reactants react to exchange their places to form two new products.
The general representation of this reaction is,
(X and A are the cations, Y and B are the anions)
Hence, the products of this reaction are, copper hydroxide, and sodium nitrate,
Answer:
TRUE
Explanation:
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