Answer:
a. absorbs energy as heat and has positive enthalpy of solution.
Explanation:
A reaction can either be exothermic or endothermic. An endothermic reaction, as the dissolution described in the question, is that which absorbs heat energy from the surroundings in order to start the reaction.
Because an endothermic reaction makes heat lost from the surroundings, the enthalpy (∆H) of the solution will be positive (+). ∆H is got by finding the difference between the enthalpy of the reactants and products and since the enthalpy of a product in endothermic reaction is more, the enthalpy change (∆T) will be positive.
Answer:
molarity = moles of solution/liters of solution
molarity = 1 mole/2 liters
molarity = 0.5 M
molarity = 50 moles/200 kg
molarity = 0.25 M
Explanation:
Answer: Friction.
Explanation: Even though the driver has taken the foot off thr gas pedal, the acceleration of the car decreases and the friction continues.
The car slows down because the opposite force of friction continues to act and the acceleration in forward direction is continuous decreasing. Hence, the car slows down.
The moon orbiting around the earth.
Answer:

Explanation:
Hello there!
In this case, according to the given information, it turns out firstly necessary to write out the described chemical reaction as shown below:

Now, we set up the expression for the calculation of the standard free energy change, considering the free energy of formation of each species, specially those of H2 and F2 which are both 0 because they are pure elements:

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