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yan [13]
2 years ago
5

The isotope 64Cu has t1/2 of 12.7 hours. If the initial concentration of this isotope in an aqueous solution is 845 ppm, what wi

ll the abundance be after 4.00 hours? To solve this problem, first use equation (7) to determine k for 64Cu; then use this k value in equation (6) to obtain the amount of 64Cu, A, remaining after 4.00 hours if the amount present at the start, A0, is 845 ppm.
Chemistry
1 answer:
Kisachek [45]2 years ago
7 0

Answer:

A = 679.2955 ppm

Explanation:

In this case, we already know that 64Cu has a half life of 12.7 hours. The expression to use to calculate the remaining solution is:

A = A₀ e^-kt

This is the expression to use. We have time, A₀, but we do not have k. This value is calculated with the following expression:

k = ln2 / t₁/₂

Replacing the given data we have:

k = ln2 / 12.7

k = 0.0546

Now, let's get the concentration of Cu:

A = 845 e^(-0.0546*4)

A = 845 e^(-0.2183)

A = 845 * 0.8039

A = 679.2955 ppm

This would be the concentration after 4 hours

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White raven [17]

Answer:

son 12.6 gramos de HF

Explanation:

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5 0
2 years ago
What are the 3 critical components of an electromagnet and what purpose do they each serve?
WARRIOR [948]

Answer:

A source of electricity, a wire coil, and an iron core  

Explanation:

An electromagnet has three critical components:

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This is often a battery.

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4 0
2 years ago
A patient needs to be given exactly 500 ml of a 5.0% (w/v) intravenous glucose solution. the stock solution is 35% (w/v). how ma
N76 [4]
In this question, the <span>patient needs to be given exactly 500 ml of a 5.0%. The content of the glucose should be:
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6 0
2 years ago
Read 2 more answers
Consider NH3 and PH3. Electronegativities: P = 2.1, H = 2.1, N=3.0. Which statement is false?
NikAS [45]

Answer:

The P-H bonds are more polar than the N-H bonds.

Explanation:

Phosphine is a polar molecule with non-polar bonds. The phosphorus atom is bonded to three hydrogen atoms and the phosphorus atom has a lone pair of electrons. Since hydrogen and phosphorus are equal in electronegativity, it implies that they attract the shared pairs of electrons the same amount,hence bonding electrons are shared equally making the covalent bonds non-polar.

The lone pair of electrons on phosphorus causes the molecule to be asymmetrical with respect to charge distribution this is why the molecule is polar even though the are non-polar bonds in the molecule.

Looking at the values of electro negativity stated in the question, one can easily see that the difference in electro negativity between nitrogen and hydrogen is 0.9 while the difference in electro negativity between phosphorus and hydrogen is zero. It is clear that NH3 is naturally more polar than PH3 since each individual N-H bond in NH3 is a polar bond while the individual P-H bonds in PH3 are nonpolar.

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2 years ago
There are two types of nucleic acids, dna and rna. nearly all organisms use dna, not rna, as the central repository for genetic
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Found the choices. Pls see attachment. 

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