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Jobisdone [24]
3 years ago
11

Technetium has a half-life of six hours. If you obtain 100g of a pure technetium sample, after 18 hours how much of the pure sub

stance will be remaining?
Chemistry
1 answer:
Butoxors [25]3 years ago
5 0

Answer: 12.5 grams.

Explanation:

You can find the amount of pure substance remaining by using the half-life formula:

Q_{1}=Q(\frac{1}{2})^{\frac{t}{t2} }

Where t is the amount of time, and t2 is the half life of the substance.

Substituting our values for the variables, we get this equation:

Q_{1} = 100(\frac{1}{2})^3\\\\Q_{1} = 100(\frac{1}{8})\\\\Q_{1} = 12.5

After 18 hours, there will be 12.5 grams of the substance remaining.

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steposvetlana [31]

Answer:

5.83 mol.

Explanation:

  • From the balanced reaction:

<em>2Al + 3Ag₂S → 6Ag + Al₂S₃,</em>

It is clear that 2 mol of Al react with 3 mol of Ag₂S to produce 1 mol of Ag and 1 mol of Al₂S₃.

Al reacts with Ag₂S with (2: 3) molar ratio.

<em>So, 2.27 mol of Al reacts completely with 3.4 mol of Ag₂S with (2: 3) molar ratio.</em>

<em />

  • The limiting reactant is Ag₂S.
  • The excess "left over" reactant is Al.

The reamining moles of excess reactant "Al" = 8.1 mol - 2.27 mol = 5.83 mol.

6 0
3 years ago
Witch element has the smallest radius
natali 33 [55]

Answer: Helium has the smallest radius.

Explanation: Helium has the smallest atomic radius. Due to nuclear charges and stuff ect-

8 0
1 year ago
Sulfur trioxide is a gas that reacts with liquid water to produce aqueous sulfuric Acid or acid rain what is the equation for th
bearhunter [10]

Answer:

SO₃(g) + H₂O(l) → H₂SO₄(aq)

Explanation:

The<em> molecular formula for the involved species</em> are:

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  • Water = H₂O
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With the above information in mind we can proceed to write the reaction equation:

  • SO₃(g) + H₂O(l) → H₂SO₄(aq)
5 0
2 years ago
The molecular weight of NaCl is 58.44 grams/mole. If you had a 1.0 molar solution (1.0 M), you would have to put 58.44 g of salt
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Molarity is expressed as the number of moles of solute per volume of the solution. For example, we are given a solution of 2M NaOH this describes a solution that has 2 moles of NaOH per 1 L volume of the solution. To calculate the moles of NaCl in 1.0 M of solution, we simply multiply the volume given of the solution.

moles NaCl = 1.0 M (0.100 L ) = 0.10 mol NaCl --------> OPTION B
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3 years ago
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wlad13 [49]

Answer:

This is one of the factors that affects chemical reactions

Temperature:This is because when the temperature is raised energy in form of heat is supplied to the reacting particles and so the rate of reaction is increased.

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