Answer:
Physical change because even though gas formation was observed, the water was undergoing a state change, which means that its original properties are preserved.
Explanation:
The gas formation seen is in fact the transition of the liquid water to a gas state, not the formation of a new gas.
Explanation:
mass = Moles * molar mass
molar mass of BaSO4 = 112+32+64= 208
= 1.72*208 = 357.76
Explanation:
Given
The enthalpy of formation of RbF (s) is –557.7kJ/mol
The standard enthalpy of formation of RbF (aq, 1 m) is –583.8 kJ/mol
The enthalpy of solution of RbF = Enthalpy of RbF (aq) - Enthalpy of formation of RbF (s)
= -583.8 - (-557.7) kJ/mol
= -26.1 kJ/mol
The enthalpy is negative which means that the temperature will rise when RbF is dissolved.
Answer:
Doing an Endothermic reaction, energy is absorbed from surroundings
Explanation:
Endothermic reactions:
The type of reactions in which energy is absorbed are called endothermic reactions.
In this type of reaction energy needed to break the bond are higher than the energy released during bond formation.
For example:
C + H₂O → CO + H₂
ΔH = +131 kj/mol
it can be written as,
C + H₂O + 131 kj/mol → CO + H₂
we can see that 131 kj/mol energy is taken by the reactants. So energy is absorbed from surrounding.
Exothermic reaction:
The type of reactions in which energy is released are called exothermic reactions.
In this type of reaction energy needed to break the bonds are less than the energy released during the bond formation.
For example:
Chemical equation:
C + O₂ → CO₂
ΔH = -393 Kj/mol
it can be written as,
C + O₂ → CO₂ + 393 Kj/mol
it is b forces hold matter together
A force is a push or pull on an object. Forces usually cannot be seen but their effects can. Nothing moves, changes speed, stops or changes direction without force. Heavier objects need more force to get them to move or change direction.
