1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
djyliett [7]
3 years ago
12

Uranium–232 has a half–life of 68.9 years. A sample from 206.7 years ago contains 1.40 g of uranium–232. How much uranium was or

iginally present?
Chemistry
2 answers:
Mnenie [13.5K]3 years ago
7 0

it's 11.2, other guy prob made a typo is all

givi [52]3 years ago
4 0

<u>Answer:</u> The initial amount of Uranium-232 present is 11.3 grams.

<u>Explanation:</u>

All the radioactive reactions follows first order kinetics.

The equation used to calculate half life for first order kinetics:

t_{1/2}=\frac{0.693}{k}

We are given:

t_{1/2}=68.9yrs

Putting values in above equation, we get:

k=\frac{0.693}{68.9}=0.0101yr^{-1}

Rate law expression for first order kinetics is given by the equation:

k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}

where,

k = rate constant = 0.0101yr^{-1}

t = time taken for decay process = 206.7 yrs

[A_o] = initial amount of the reactant = ?

[A] = amount left after decay process = 1.40 g

Putting values in above equation, we get:

0.0101yr^{-1}=\frac{2.303}{206.7yrs}\log\frac{[A_o]}{1.40}

[A_o]=11.3g

Hence, the initial amount of Uranium-232 present is 11.3 grams.

You might be interested in
Why do scientific theories change?
Sergio039 [100]
Scientific theories change because<span> </span>theories<span> may be modified or overturned as new evidence and perspective emerges. ... The process of </span>theory change<span> may take time and involve controversy, but eventually the </span>scientific<span> explanation that is more accurate will be accepted. Hoped you get it!</span>
5 0
3 years ago
Read 2 more answers
Has highest melting point of two bonds
Liono4ka [1.6K]

Answer:

Ionic compounds

Explanation:

7 0
3 years ago
Gallium chloride is formed by the reaction of 2.25 L of a 1.50 M solution of HCl according to the following equation: 2Ga 6HCl -
Setler79 [48]

Answer:

198.56g of GaCl3

Explanation:

We'll begin by calculating the number of mole HCl in 2.25 L of a 1.50 M solution of HCl. This is illustrated below:

Molarity of HCl = 1.50 M

Volume = 2.25 L

Mole of HCl =..?

Molarity = mole /Volume

1.5 = mole /2.25

Cross multiply

Mole = 1.5 x 2.25

Mole of HCl = 3.375 mole

Next, we shall determine the number of mole Gallium chloride, GaCl3 produced from the reaction. This is shown below:

2Ga + 6HCl —> 2GaCl3 + 3H2

From the balanced equation above,

6 moles of HCl reacted to produce 2 moles of GaCl3.

Therefore, 3.375 mole of HCl will react to produce = (3.375 x 2)/6 = 1.125 mole of GaCl3.

Therefore, 1.125 moles of GaCl3 were produced from the reaction.

Next, we shall convert 1.125 mole of GaCl3 to grams. This is illustrated below:

Molar mass of GaCl3 = 70 + (35.5x3) = 176.5g/mol

Mole of GaCl3 = 1.125 mole

Mass of GaCl3 =..?

Mole = mass /Molar mass

1.125 = mass of GaCl3 /176.5

Cross multiply

Mass of GaCl3 = 1.125 x 176.5

Mass of GaCl3 = 198.56g

Therefore, 198.56g of GaCl3 were produced from the reaction.

7 0
3 years ago
Help............???????
balandron [24]

B. .175


Hope it helps!

4 0
2 years ago
Please help <br><br> 10 POINTS!!!
salantis [7]
The answer would be C as in cat and D as in dog your welcome i hope this help
5 0
2 years ago
Other questions:
  • Based on these ideas, what are the pro's and con's for both Sexual Reproduction and Asexual reproduction?
    11·1 answer
  • A mass of 100.0 g of NaCl is added to 100.0 mL of water, but not all of it dissolves. A mass of 59.5 grams of NaCl solid remains
    11·2 answers
  • If the K a of a monoprotic weak acid is 1.0 × 10 − 6 , what is the [ H + ] of a 0.22 M solution of this acid?
    7·1 answer
  • A major problem caused by humans is the contamination and depletion of _____ resources. A. solar B. water C. wind
    7·2 answers
  • A student mixed some yellow sulfur powder with some iron filings. She was able to take the iron out of the sulfur by using a mag
    11·1 answer
  • The number of particles of 0.2<br> mole​
    14·1 answer
  • How long does it take light to travel from the Earth to the Sun? The speed of light is 2.998×10^5 km/s and the Sun is 1.496×10^8
    6·1 answer
  • Which option is a key point of cell theory? Cells can repair neighboring cells, but not themselves.Cells can repair neighboring
    14·1 answer
  • What are 6 things you would do to a new substance to determine if it was a metal? I need help!
    5·2 answers
  • A kettle takes 3 minutes to boil. Calculate what part of an hour it is.​
    11·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!