Answer:
HS+Na=>NaS+1/2H2(here HS- acts as an acid)
HS-. + HCl=> H2S(g)+ Cl-(here HS- acts as a base)
Answer:
electroluminescence is a production of light by the flow of electrons, as within certain crystals. An example is at most resataurants with a bright sign that either says open or closed.
Explanation:
Answer:
51 J
Explanation:
The air inside a bicycle tire pump has 27 joules of heat conducted away. By convention, when heat is released, it takes the negative sign, so Q = -27 J.
77.9 joules of work done are being done on the air inside a bicycle tire pump. By convention, when work is being done on the system, it takes the positive sign, so W = 77.9 J
We can calculate the change in the internal energy (ΔU) using the following expression.
ΔU = Q + W
ΔU = (-27 J) + 77.9 J
ΔU = 51 J
Answer: The reaction is exothermic. The value of q is -542 kJ.
Explanation:
Endothermic reactions are defined as the reactions in which energy of the product is greater than the energy of the reactants. The total energy is absorbed in the form of heat and for the reaction comes out to be positive.
Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and for the reaction comes out to be negative.
Thus 
evolves heat , it is exothermic in nature. The value of q is -542kJ.
It looks all correct to me, great job!
