<span>when it comes to adding or subtracting numbers, his final answer should have the same number of decimal places as the least precise value.
For example if you add 2 numbers; 10.443 + 3.5 , 10.443 has 3 decimal places and 3.5 has only one decimal place.
Therefore 3.5 is the less precise value.
So when adding these 2 values the final answer should have only one decimal place.
after adding we get 13.943 but it can have upto one decimal place. then the second decimal place is less than 5 so the answer should be rounded off to 13.9.
the answer is the same number of decimal places as the least precise value</span>
<span>The density of an iceberg is less than that of water and that is why it floats. It is the same as ice cubes floating on water too. Water is a very unique substance in that it is one of few compounds where cooling it past freezing point decreases its density (study hydrogen bonds). The possible answers are therefore A or C. If the majority of the ice is below the water then it should be clear from common sense that A is the correct answer as it would mostly float on the top with just a little under the surface if the answer were as low as C. See Archimedes Principle for an explanation of how much of the ice floats and how much is underwater.</span>
Answer:
ΔH of solution is expected to be close to zero.
Explanation:
When we mix two non polar organic liquids like hexane and heptane,the resulting mixture formed is an ideal solution.An ideal solution is formed when the force of attraction between the molecules of the two liquids is equal to the force of attraction between the molecules of the same type.
For instance if liquids A and B are mixed,
=
= 
Hence the condition before and after mixing remains unchanged.
Since enthalpy change is associated with inter molecular force of attraction the enthalpy change for ideal solution is zero.
More examples of ideal solutions are:
1. Ethanol and Methanol
2. Benzene and Toluene
3. Ethyl bromide and Ethyl iodide
Using charles law
v1/t1=v2/t2
v1=49ml
v2=74
t1=7+273=280k
t2=?
49/280=74/t2
0.175=74/t2 cross multiply
0.175t2=74
t2=74/0.175
t2=422k or 149celcius
<u>Answer:</u> The number of moles of gas remaining in the lungs is 0.063 moles
<u>Explanation:</u>
The relationship of number of moles and volume at constant temperature and pressure was given by Avogadro's law. This law states that volume is directly proportional to number of moles at constant temperature and pressure.
The equation used to calculate number of moles is given by:

where,
are the initial volume and number of moles
are the final volume and number of moles
We are given:

Putting values in above equation, we get:

Hence, the number of moles of gas remaining in the lungs is 0.063 moles