From the statement of Hess' law, the enthalpy of the reaction A---> C is +90 kJ
<h3>What is Hess' law?</h3>
Hess' law of constant heat summation states that for a multistep reaction, the standard enthalpy of reaction is always constant and is independent of the pathway or intermediate routes taken.
From Hess' law, the enthalpy change for the reaction A ----> C is calculated as follows:
A---> C = A ---> B + B ---> C
ΔH of A---> C = 30 kJ + 60 kJ
ΔH = 90 kJ
Therefore, the enthalpy of the reaction A---> C is +90 kJ
The above reaction A---> C can be shown in the enthalpy diagram below:
A -------------------> C (ΔH = +90 kJ)
\ /
\ / (ΔH = +60 kJ)
(ΔH = +30 J) \ /
> B
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Answer: when two elements combine, A and B, the ratio of the weight of B combining with A is always a whole number
Explanation:
Electrolytes are substances that produce ions when they dissolve in water.
What are electrolytes?
When some substances are dissolved in water, they undergo physical or chemical changes, creating ions in solution. These substances form an important class of compounds called electrolytes. Substances that do not release ions when dissolved are called non-electrolytes. A substance is said to be a strong electrolyte if the physical or chemical process that produces ions is inherently 100% efficient (all dissolved compounds produce ions). A solute is said to be a weak electrolyte if only a relatively small portion of the solute undergoes ion production processes.
By measuring the electrical conductivity of aqueous solutions containing substances, substances can be identified as strong, weak, or non-electrolyte. To conduct electricity, a substance must contain free-moving charged species. The best known is the conduction of electricity through metal wires. In this case, the mobile charged unit is the electron.
Therefore, Electrolytes are substances that produce ions when they dissolve in water.
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Scientists repeat experiments for reliability. Experiments have to be repeated, since performing an experiment only once, does not prove a scientists theory on the experiment, which they develop by performing the experiment. And then performing the experiment again or even many times to prove or disapprove their theories. Btw, before an experiment begins, the scientist will make a hypothesis of what they believe will happen. If proven correctly, they would then use those results they record throughout the experiment, from beginning to end to prove whether or not their hypothesis are correct or incorrect. Click to let others know, how helpful is it
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So that they can prove the other scientists views wrong and develop a new theory in which there is more sense and credibility.
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BASICALLY, I THINK THE ANSWER IS 1 OR 2 OR
