Heat and Thermodynamics part-(1)

F=9/5C+32
where C=centigrade temperature
F=Fahrenheit Temperature⇒
F=9/5*40+32⇒F=72+32⇒F=104
so the value of 40°C is 104°F at Fahrenheit scale.

F=9/5*C+32
⇒F=9/5*50+32
⇒F=90+32⇒F=122
so the value of 50°C at Fahrenheit scale.

There are lots of reasons for using alcohol than mercury Ans. (b) thermometric liquids. Some alcohol has a very low freezing point of about-112°C and therefore is suitable to record very low temperature. Thus, in cold countries, alcohol is preferred to mercury as a thermometric liquid.

Ethylene glycol is an organic molecule most widely used a antifreeze in automobile engines and as an industrial solvent When it is mixed with water, the freezing point of the mixture is depressed, specifically a mixture of 60% ethylene glyco and 40% water freezes at -45°C. That is why water is not frozen in the engine of cold countries.

Absolute zero is the lowest possible temperature at which point the atoms of a substance transmit no thermal energy.They are completely at rest .It is 0 on the kelvin scale which translate to -273.15 degree celsius.

Density is defined as the ratio of the mass and the volume or mass per unit volume (density=mass/volume)
as the temperature increases most of the materials expend or increase their volume this is the result in a decrease in density.