<span>The choices are as follows:
h2o + 2o2 = h2o2
fe2o3 + 3h2 = 2fe + 3h2o
al + 3br2 = albr3
caco3 = </span><span>cao + co2
The correct answers would be the second and the last option. The equations that are correctly balanced are:
</span> fe2o3 + 3h2 = 2fe + 3h2o
caco3 = cao + co2
To balance, it should be that the number of atoms of each element in the reactant and the product side is equal.
The equation described by the kb value is 5.21 x
.
The potential of Hydrogen is what pH is formally known as. The negative logarithm of the concentration of H+ ions is known as pH. Thus, the definition of pH as the amount of hydrogen is provided. The hydrogen ion concentration in a solution is described by the pH scale, which also serves as a gauge for the solution's acidity or basicity.
Assuming PO₄³⁻ (the phosphate anion).
PO₄³- + H₂O ==> HPO₄²⁻ + OH⁻
Kb = [HPO₄²⁻][OH⁻] / [PO₄³⁻]
We can find the [OH⁻] from the pH of 12.70.
pH + pOH = 14
14.0 - 12.7 = 1.3 = pOH
[OH] = 1x
[OH-] = 5.0x
M
[HPO₄²⁻] = 5.0x
M
Kb = (5.0x
)2 / 0.48
= 2.5x
/ 0.48
Kb = 5.21 x 
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Answer:
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Answer:
To ensure provide and reliable data
Explanation:
Calibration ensures precise repeatable performance while preventing pipetting errors. Just the way measurement standards are established to distinguish valid and invalid processes, pipette calibration standards are designed to ensure the best pipette accuracy.