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Reil [10]
3 years ago
15

Sodium-24 has a half life how much sodium-24 will remain in an 18 g sample after 75 hours

Chemistry
1 answer:
frutty [35]3 years ago
3 0

Answer:

\boxed{\text{0.56 g}}

Explanation:

The half-life of Na-24 (15 h) is the time it takes for half of it to decay.  

After one half-life, half (50 %) of the original amount will remain.  

After a second half-life, half of that amount (25 %) will remain, and so on.  

We can construct a table as follows:  

  No. of                 Fraction          Mass

<u>half-lives   t/da   Remaining   Remaining/g </u>

      0             0           1                      18

       1            15            ½                    9.0

      2           30            ¼                    4.5

      3           45            ⅛                    2.2

      4           60            ⅟₁₆                   1.1

      5           75            ⅟₃₂                   0.56

      6           90           ⅟₆₄                   0.28

We see that  \boxed{\textbf{0.56 g}} remain after five half-lives (75 h).

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The volume (in mL) of 0.242 M NaOH solution needed for the titration reaction is 39.44 mL

<h3>Balanced equation </h3>

CH₃CH₂COOH + NaOH —> CH₃CH₂COONa + H₂O

From the balanced equation above,

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<h3>How to determine the volume of NaOH</h3>
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  • Volume of base, KOH (Vb) =?

MaVa / MbVb = nA / nB

(0.204 × 46.79) / (0.242 × Vb) = 1

Cross multiply

0.242 × Vb = 0.204 × 46.79

Divide both side by 0.242

Vb = (0.204 × 46.79) / 0.242

Vb = 39.44 mL

Thus, the volume of NaOH needed for the reaction is 39.44 mL

Learn more about titration:

brainly.com/question/14356286

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kodGreya [7K]

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