Answer:
NaCl + Fe2+ ---> FeCl2 + Na+
Single replacement
Explanation:
Na is replaced by Fe2+ to form FeCl2, and that is the only replacement. Thus, it is single replacement.
Answer:
-100 kJ
Explanation:
We can solve this problem by applying the first law of thermodynamics, which states that:
where:
is the change in internal energy of a system
Q is the heat absorbed/released by the system (it is positive if absorbed by the system, negative if released by the system)
W is the work done by the system (it is positive if done by the system, negative if done on the system)
For the system in this problem we have:
W = +147 kJ is the work done by the system
Q = +47 kJ is the heat absorbed by the system
So , its change in internal energy is:
Answer is: an instant ice pack becoming cold, splitting a gas molecule and baking bread.
<span>Endothermic reaction
is chemical reaction that absorbs more energy than it releases.
</span>In ice pack, <span>reaction absorbs heat from the surroundings (endothermic reaction), lowering the surrounding temperature.
For splitting molecule and baking bread we must add energy to break bonds between atoms.</span>
Answer:
Scientific Method.
Explanation:
A scientific method is basically a method or a process when you conduct an experiment. Normally, the process goes like this:
1. You make like a question or something that you want to investigate, it's like the aim of the experiment.
2. You make an experiment and a hypothesis. A hypothesis is basically a guess on how the results of the experiment would turn out. You don't have to be correct for the hypothesis since there is no right or wrong answer.
3. Conduct the experiment. I don't think this needs a detailed explanation since experiments vary from one another.
4. Collect results. The data you collect come in different ways based on your experiment, but it is crucial you get data so that you can answer your question in 1.
5. Make inferences. You can't directly get a conclusion or answer from the results, so inferences are needed.
6. Craft a conclusion or answer. This is the final step when conducting an experiment and the part where you have the answer you needed when you conducted the experiment :)
Answer:
3.59x10^21 molecules
Explanation:
1mole of a substance contains 6.02x10^23 molecules.
Therefore, 1mole of C8H18 will also contain 6.02x10^23 molecules
1mole of C8H18 = (12x8) +(18x1) = 96 + 18 = 114g.
1mole (i.e 114g) oh C8H18 contains 6.02x10^23 molecules.
Therefore, 0.68g of C8H18 will contain = (0.68 x 6.02x10^23)/114 = 3.59x10^21 molecules
