Calculate the enthalpy of the formation of butane, C4H10, using the balanced chemical equation and the standard value below:
4C(s) + 5H2(g) => C4H10(g)
Standard enthalpy of formation values:
(Delta Triangle)H^0 of C(s)= -393.5kJ/mol
(Delta triangle)H^0f of H2(g)=-285.8 kJ/mol
(Delta triangle)H^0f of C4H10(g)=-2877.6kJ/mol

a mercury barometer is a device that uses the physical properties of mercury in a tube to measure barometric pressure. mercury barometers are used for : -

1. measurement of atmospheric pressure  

2. determining the altitude of a place

3. weather forecasting

4. calibration and checking of aneroid barometers

5. application in fluid mechanics

6. measurement of pressure in aircrafts

7. surface weather analysis

8. preparation of barographs

9. usage in physical sciences like physics, astronomy & chemistry

10. preparation of aircraft altimeters

characteristics of mercury barometer : -

1.used to define and measure atmospheric pressure.

2.on the average at sea level the column of mercury rises to a height of about 760 mm.

3.this quantity is equal to 1 atmosphere.

4.it is also known as standard atmospheric pressure.

5.a barometer in which the weight of a column of mercury in a glass tube with a sealed top is balanced against that of the atmosphere pressing on an exposed cistern of mercury at the base of the mercury column, the height of the column varying with atmospheric pressure.

your answer would be “dry”

it forms an anion that has a larger radius. anions have a negative charge and are larger than the original atom.

catya that's not even a b or c