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strojnjashka [21]
2 years ago
11

Help please!!

Chemistry
1 answer:
frez [133]2 years ago
7 0

Answer:

6.25%

Explanation:

Given data:

Half life of lutetium-117 = 6.75 days

Percentage remaining after 27 days = ?

Solution;

Number of half lives = Time elapsed / half life

Number of half lives = 27 days / 6.75 days

Number of half lives = 4

At time zero = 100%

At first half life = 100%/2 = 50%

At second half life = 50%/2 = 25%

At 3rd half life = 25%/2 = 12.5%

At 4th half life = 12.5%/2 = 6.25%

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MakcuM [25]

B. false is the answer of this question

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In the reaction N2O4(g) 2NO2(g), what changes in color would you expect as pressure is increased at constant temperature?
skelet666 [1.2K]

Answer:

Brown color of the solution decreases

Explanation:

NO_2 is brown in color whereas N_2O_4 is colorless.

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As per the Le Chatelier's principle, if pressure of a equilibrium is increased, the equilibrium will shift in the direction having fewer no. of moles of gases.

In the given equilibrium, NO_2 side has more no. of moles. So on increasing pressure, equilibrium will shift towards the side of N_2O_4 or more formation of N_2O_4 will take place.

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6 0
3 years ago
Given 700 ml of oxygen at 7 ºC and 106.6 kPa pressure, what volume does it take at 27ºC and 66.6 kPa pressure
o-na [289]

Answer:

The volume is 1.2L

Explanation:

Initial volume (V1) = 700mL = 0.7L

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6 0
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5 0
2 years ago
How many hydrogen atoms are in 5.20 mol of ammonium sulfide?
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8 0
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