Answer:
The correct answer is 0.020 M.
Explanation:
To solve this problem, we can use the equation M1V1 = M2V2, where M represents the molarity of the solution and V represents the volume of solution. Since we are given that the original solution is 50 mL and 0.40 M, these values are V1 and M1, respectively. The solution after dilution has a volume of 1000 mL, so this value is V2. We are solving for the molarity after dilution, which represents M2.
If we plug in the values specified above, we get the following:
M1V1 = M2V2
(0.40 M)(50.0 mL) = (M2)(1000.0 mL)
Solving for M2, we get:
M2 = 0.020 M
Notice that our answer has 2 significant figures because 0.40 has 2 significant figures, the least of any values given in the problem.
Therefore, the answer is 0.020 M.
Hope this helps!
Answer:
128 g/mol
Explanation:
The molar mass is how much a mol of the substance weight.
In this question the weight is given (1.570 g).
To find the number of moles in the sample, we use the ideal gas law: PV=RnT
P= 1atm
V= 577mL= 0.577L
R (universal gas constant)= 0.08206(
)
n= number of moles
T= 300°C= 573.15K
Solving for n:
n=
<em>k</em>
n=0.0123mol
Molar mass=
Molar mass=128
It gives each organelle in the cell its own specific function
Answer:
(C) HClO, pKa = 7.54
Explanation:
A buffer is a solution that can resist abrupt changes in pH when acids or bases are added. It is formed by two components:
- A weak acid and its conjugate base.
- A weak base and its conjugate acid.
In this case, acid and base are defined according to Bronsted-Löwry theory, which states that acids are substances that <em>release H⁺</em> and bases are substances that <em>accept H⁺. </em>Therefore, when an acid loses an H⁺ transforms into its conjugated base. For example, HF/F⁻ is a conjugate acid-base pair.
In buffers, when an acid is added, it reacts with the base to diminish its amount:
F⁻ + H⁺ ⇄ HF
Also in buffers, when a base is added, it reacts with the acid to diminish its amount:
HF + OH⁻ = F⁻ + H₂O
The optimum pH range of work of a buffer system (known as buffer range) is between 1 unit less and 1 unit more of pH than its pKa.
So, the buffer formed by HClO/ClO⁻ works optimally in the pH range 6.54-8.54. Since pH = 8.10 is in that interval, this would be the optimal choice.