Answer:
C-18
Explanation:
Step one follow order of operations
Add and subtract from left to right(-5)+(7)=2-(-4)+(12)
STEP 2
Apply negative Rule -(-4)=+4=2+4+(12)
then add 2+4+12=18
Moles= mass divided by molar mass
Molar mass= 12.01(4) + 1.01(10)
= 58.14g/mol
Moles=14.5g / 58.14g/mol
=0.249
Therefore there are approx 0.249 moles in a 14.5g sample of C4H10
Sodium(Na) is the limiting reagent.
<h3>What is Limiting reagent?</h3>
The reactant that is totally consumed during a reaction, or the limiting reagent, decides when the process comes to an end. The precise quantity of reactant required to react with another element may be estimated from the reaction stoichiometry.
How do you identify a limiting reagent?
The limiting reactant is the one that is consumed first and sets a limit on the quantity of product(s) that can be produced. Calculate how many moles of each reactant are present and contrast this ratio with the mole ratio of the reactants in the balanced chemical equation to get the limiting reactant.
Start by writing the balanced chemical equation that describes this reaction

Notice that the reaction consumes 2 moles of sodium metal for every 1 mole of chlorine gas that takes part in the reaction and produces 2 moles of sodium chloride.
now we can see that we have 3 moles of sodium and 3 moles of chlorine, according to question. so, we can say that sodium is the limiting reagent in the given situation.
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This answer is 24 because 2.17 x 10 -8 is 24 so that would be your answer
Answer:
Both <u>elements </u>and <u>compounds</u> can be classifies as pure substances because they have distinct properties and composition.
Explanation:
Elements and compounds are considered as pure substances because both are always formed form are have same kind of atoms.
For example,
Carbon dioxide is compound. It always consist of one carbon atom and two oxygen atoms.
Water is compound it always have same kind of atoms two hydrogen and one oxygen that's why compounds are considered as pure substances.
Same is the case with elements. For example,
Hydrogen is element and it always consist of H atoms.
Iron is another element and it always have iron atoms.
So elements and compounds are always consist of same substances that's why they are considered as pure.