d = √((x1 - x2)2 + (y1 - y2)2)
( -2 , 5 ) ( 12 , -1 )
↑ ↑ ↑ ↑
x1 y1 x2 y2
d = √((-2 - 12)2 + (5 - (-1))2) = √((-14)2 + 62) = √(196 + 36) = √232 = 2√58 ≈ 15.23
Answer:
5.0 x 10⁹ years.
Explanation:
- It is known that the decay of a radioactive isotope isotope obeys first order kinetics.
- Half-life time is the time needed for the reactants to be in its half concentration.
- If reactant has initial concentration [A₀], after half-life time its concentration will be ([A₀]/2).
- Also, it is clear that in first order decay the half-life time is independent of the initial concentration.
- The half-life of K-40 = 1.251 × 10⁹ years.
- For, first order reactions:
<em>k = ln(2)/(t1/2) = 0.693/(t1/2).</em>
Where, k is the rate constant of the reaction.
t1/2 is the half-life of the reaction.
∴ k =0.693/(t1/2) = 0.693/(1.251 × 10⁹ years) = 5.54 x 10⁻¹⁰ year⁻¹.
- Also, we have the integral law of first order reaction:
<em>kt = ln([A₀]/[A]),</em>
where, k is the rate constant of the reaction (k = 5.54 x 10⁻¹⁰ year⁻¹).
t is the time of the reaction (t = ??? year).
[A₀] is the initial concentration of (K-40) ([A₀] = 100%).
[A] is the remaining concentration of (K-40) ([A] = 6.25%).
∴ (5.54 x 10⁻¹⁰ year⁻¹)(t) = ln((100%)/( 6.25%))
∴ (5.54 x 10⁻¹⁰ year⁻¹)(t) = 2.77.
∴ t = 2.77/(5.54 x 10⁻¹⁰ year⁻¹) = 5.0 x 10⁹ years.
Answer:
The cell potential is 0.0296V
Explanation:
Please see the attachment below
Answer: There are 0.006 moles of acid in the flask.
Explanation:
Given: 
= 21.35 mL, 
= 0.150 M
= 25.0 mL, 
= ?
Formula used to calculate molarity of 
is as follows.
Substitute the values into above formula as follows.
As molarity is the number of moles of a substance present in a liter of solution.
Total volume of solution = 
= 21.35 mL + 25.0 mL
= 46.36 mL (1 mL = 0.001 L)
= 0.04636 L
Therefore, moles of acid required are calculated as follows.
Thus, we can conclude that there are 0.006 moles of acid in the flask.
<u>Answer:</u> The correct answer is Option D.
<u>Explanation:</u>
We are given that car travels with a speed of 80 km/hr and we need to convert it into hm/s.
For that we use the conversions:
1 kilometer = 10 hectometer
And, 1 hour = 3600 seconds
To convert the quantity into hm/s, we multiply the numerator which is 80 by 10 to convert the whole quantity into hm/hr and now, to convert the result into hm/s finally, we divide the result by 3600.
Hence, the correct answer is option D.
