Answer:
open system
Coffee held in a cup is an open system because it can exchange matter water vapors and energy heat with the surroundings.
Water can be turned to ice if to cold gas if to hot
ice can turn to water if to hot and stay the same if to cold
gas will turn to water if to hot and freeze to ice if to cold and the pattern keeps going like that.
hope this helps
Answer:
The specific heat of the alloy 
Explanation:
Mass of an alloy
= 25 gm
Initial temperature
= 100°c = 373 K
Mass of water
= 90 gm
Initial temperature of water
= 25.32 °c = 298.32 K
Final temperature
= 27.18 °c = 300.18 K
From energy balance equation
Heat lost by alloy = Heat gain by water
[
-
] =
(
-
)
25 ×
× ( 373 - 300.18 ) = 90 × 4.2 (300.18 - 298.32)

This is the specific heat of the alloy.
Actually the correct answer must be:
The limiting reactant in the reaction is the one which has
the lowest ratio of moles available
over coefficient in the balanced equation
This is because the actual mass or number of moles of the
reactant does not directly dictate if it is a limiting reactant, this must be
relative to the other reactants.
So the answer is:
e. none of the above
<span>The average molar bond enthalpy of the carbon-hydrogen bond in a CH4 molecule is 416 KJ/mol.
(+716.7 + (4 x 218) - (- 74.6) ) / 4
= + 1663.3 / 4
= 416</span>