I'm guessing D or C, remember that the noble gases cannot combine
The correct answer is - A) The major constituents of air are gaseous elements.
With the statement ''the major constituents of air are gaseous elements'' we can easily conclude that the air is a mixture. The reason for that is that we have a plural usage of the word element, elements, which mean that there are multiple elements that make up the air.
The air is indeed predominantly a mixture of gaseous elements. The most abundant gas in the air being the nitrogen with 78.9%, oxygen with 20.95%, argon 0.93%, and carbon dioxide 0.04%, with lesser amounts of other gases also be present in it. The water vapor is also present in the air, though it is variable, being around 1% at sea level, but only 0.4% over the entire atmosphere.
The first statement (Matter is neither created nor destroyed) is correct.
The second statement would violate the law of conservation of mass (I will refer to this as LCM), as it would mean matter can "flow" into the universe, but not out, meaning the total matter will never be less than it was before.
The third statement violates LCM because it means matter is created during a reaction, which is not true.
The last statement violates LCM because it means matter is lost during a reaction, which is not true.
Answer:
4.07L of a 0.110M NaF are needed
Explanation:
Based on the reaction:
SrCl₂(aq)+2NaF(aq)⟶SrF₂(s)+2NaCl(aq)
<em>1 mole of strontium chloride react with 2 moles of NaF</em>
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361mL of 0.620M SrCl₂ solution has:
0.361L ₓ (0.620mol / L) = 0.22382 moles SrCl₂.
Moles of NaF for a complete reaction must be:
0.22382 moles SrCl₂ ₓ (2 mol NaF / 1 mol SrCl₂) = <em>0.44764 moles of NaF</em>
If you have a solution of 0.110M NaF, the moles of NaF needed are:
0.44764 moles of NaF ₓ (1L / 0.110mol NaF) = <em>4.07L of a 0.110M NaF are needed</em>
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