Explanation:
The pH of a substance can be found by using the formula
where [ H+ ] is the hydrogen ion concentration in the substance
From the question
[ H+ ] = 2.1 × 10-¹² M
To find the pH substitute the value into the above formula
We have
We have the answer as
<h2>pH = 11.7 </h2>
The solution is basic since it lies in the basic region that is from 8 to 14
Hope this helps you
Sharon earns $25 per item. This means that this number is increasing with each item sold, then you will have a variable with this number, such as 'x'.
Plus a base salary of $100 per week. This means that this number is always true for each week and will not change when looking at a weekly perspective.
How many items must she sell to earn at least $700 per week. This is the end goal or even slightly over $700.
To set it up:
25x + 100 ≥ 700
To solve:
25 x + 100 ≥ 700
- 100 -100
______________
25x ≥ 600
___ ___
25 25
_______________
x ≥ 24
Interpret:
Sharon must sell at least 24 items.
Regards!
Boyle's law, which summarizes these observations, states that: the volume of a certain amount of gas, which is maintained at a constant temperature, is inversely proportional to the pressure exerted, which is summarized in the following expression:
P.V = constant or P = 1 / V
Example:
An inflated balloon with a volume of 0.55L at sea level (1.0 atm) is allowed to rise to a height of 6.5 km, where the pressure is about 0.40 atm.
Assuming that the temperature remains constant, what is the final volume of the balloon?
Reasoning and solution:
Note that the number of moles and the temperature of the gas remain constant, so Boyle's law is used. From the equation:
P1V1 = P2 V2
Where P1 = 1 atm, V1 = 0.55L and P2 = 0.40 atm, as well
V2 = V1 x (P1 / P2) = 0.55 L x (1 atm / 0.40 atm) = 1.4 L
When the pressure is reduced (at a constant temperature), the volume increases. The final volume is greater than the initial volume, so the answer is reasonable.
N(NaOH)=0.0688 mol
v=0.250 L
c=n(NaOH)/v
c=0.0688/0.250=0.2752≈0.28 mol/L
0.28 M
Answer:
4.907 × 10^-19 J
Explanation:
The energy of the lasers in a Blu-ray player can be calculated by using;
E = hf
Where;
E = Energy of laser (J)
h = Planck's constant (6.626 × 10^-34 J/s)
f = frequency (Hz)
However, the frequency must be known first in order to calculate the energy. The frequency can be calculated using the formula:
f = v/λ
Where:
λ = wavelength (4.05x10−7 m.)
v = speed of light (3 × 10^8m/s)
f = frequency (Hz)
f = 3 × 10^8 ÷ 4.05 x 10^−7
f = 0.7407 × 10^(8 + 7)
f = 0.7407 × 10^15
f = 7.407 × 10^14 Hz
Using E = hf
E = 6.626 × 10^-34 × 7.407 × 10^14
E = 49.07 × 10^(-34 + 14)
E = 49.07 × 10^-20
E = 4.907 × 10^-19 J