According to the question, the determined melting point of the compound is 112.5-113.0oC. When the solidified compound was retried, the melting point was found to be 133.6-154.5oC. This greater range higher than 112°C is caused by reusing samples leads to errors.
A pure sample is known by its sharp melting point. A pure sample does not melt over a large range. We can see this in the predetermined melting points of the pure sample(112.5-113.0oC).
However, reusing a sample introduces errors because the pure sample may become contaminated leading to a larger and higher range of melting point (133.6-154.5oC) which is far above 112°C.
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The answer is A.Hope this helps
Answer:
With billions of moving particles colliding into each other, an area of high energy will slowly transfer across the material until thermal equilibrium is reached (the temperature is the same across the material).
If one starts with 0.020 g of Mg, 0.0008 moles of H2 would be made if the reaction is complete.
Going by the balanced equation of reaction in the image, 1 mole of Mg will produce 1 mole of H2 in a complete reaction.
If 0.020 g of Mg is started with:
mole of Mg = mass/molar mass
= 0.020/24.3
= 0.0008 moles
Since the mole of Mg to H2 is 1:1, thus, 0.0008 moles of H2 will also be made from the reaction.
More on stoichiometry can be found here: brainly.com/question/9743981
