Answer:
1-46
2-18
Explanation:
c=12 H=1 O=16
ethanol (12×2)+(6×1)+(16)=46
water (2×1)+(16)=18
Conservation of mass can be checked in an experiment . There are three steps to do it in a best way:
1. Weigh all the equipment and materials required in the experiment before the experiment.
2. Avoid spillage and evaporation during the experiment.
3. Weigh all the equipment and materials after the experiment.
If the mass is conserved then weight from step 1 is equal to weight from step 3.
Answer:
669.48 kJ
Explanation:
According to the question, we are required to determine the heat change involved.
We know that, heat change is given by the formula;
Heat change = Mass × change in temperature × Specific heat
In this case;
Change in temperature = Final temp - initial temp
= 99.7°C - 20°C
= 79.7° C
Mass of water is 2000 g ( 2000 mL × 1 g/mL)
Specific heat of water is 4.2 J/g°C
Therefore;
Heat change = 2000 g × 79.7 °C × 4.2 J/g°C
= 669,480 joules
But, 1 kJ = 1000 J
Therefore, heat change is 669.48 kJ
The ml is also called as the magnetic quantum number. The value
of ml can range from –l to +l including zero. Hence all of the possible values for ml given
that l = 2 are:
<span>-2, -1, 0, + 1, + 2</span>
Thallium has got 81 protons
<u>Have a nice days.......</u>