Select the correct answer. What is the SI unit of time?
2 answers:
Option A: second
SI units are international system of units. This is defined as a system of units of physical quantities such as mass, length, temperature, current etc. Some of the physical units are gram, meter, second etc. along with the set of prefixes which indicates the multiplication and division with some power of 10.
For same physical quantities, these units are inter convertible For example,
and,
Here, g (gram), kg (kilogram) and mg (milligram) all are units of mass.
The units of time are second, minute, hour, day and year. Here, second is the SI unit and all the units are inter convertible as follows:
1 year=365 days
1 day=24 hours
1 hour=60 minutes
1 minute-60 seconds
Thus, the SI unit of time is second.
You might be interested in
Answer : 51.8 g of nitrogen are needed to produce 100 grams of ammonia gas.
Solution : Given,
Mass of = 100 g
Molar mass of = 27 g/mole
Molar mass of = 28 g/mole
First we have to calculate moles of .
The given balanced chemical reaction is,
From the given reaction, we conclude that
2 moles of produced from 1 mole of
3.7 moles of produced from
of
Now we have to calculate the mass of .
Mass of = Moles of
× Molar mass of
Mass of = 1.85 mole × 28 g/mole = 51.8 g
Therefore, 51.8 g of nitrogen are needed to produce 100 grams of ammonia gas.