Answer:
Joule - J
Explanation:
As energy is defined via work, the SI unit of energy is the same as the unit of work – the joule (J).
Mass of Na2SO4= 514.18 grams
<h3>Further explanation</h3>
Given
423.67 g of NaCl
Required
mass of Na2SO4
Solution
Reaction
2NaCl + H2SO4 → Na2SO4 + 2HCl
mol NaCl :
= 423.67 g : 58.5 g/mol
= 7.24
From the equation, mol Na2SO4 :
= 1/2 x mol NaCl
= 1/2 x 7.24
= 3.62
Mass Na2SO4 :
= 3.62 mol x 142,04 g/mol
= 514.18 grams
Answer : The approximate relation Celsius = 1/2 Fahrenheit is a better approximation at higher temperatures
Explanation :
The formula for Celsius to Fahrenheit conversion is

At lower temperature the value that needs to be subtracted (32) is large enough as a result the approximation "celsius = 1/2 fahrenheit " does not seem valid.
For example, 50 F is 10°C.

This is almost 1/5 of Fahrenheit temperature.
But at higher temperatures , the value becomes insignificant and also the ratio 5/9 tend to be equal to 0.5.
For example, 2000 F is 1093°C

This is almost half of Fahrenheit temperature.
Therefore , the approximate relation Celsius = 1/2 Fahrenheit is a better approximation at higher temperatures
A local community needs to provide more electricity for its growing population. Currently, the community's electricity needs are met by coal-burning power plants several kilometres away. Citizens are concerned that burning more coal will produce too much air pollution.
Which of the following could be used as an alternative energy resource to help minimise air pollution in this community?
A. hydroelectric energy
B. solar energy
C. wind energy
<u>D. all of these
</u>
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