<span>The best choice is hypochlorous acid nitrous acid (HNO2) because it has the nearest value of pK to the desired pH.
pKa of </span>nitrous acid<span> is 3.34
If we know pKa and pH values, we can calculate the required ratio of conjugate base (NO2⁻) to acid (HNO2) from the following equation:
pH=pKa + log(conc. of base)/( conc. of acid)
</span><span>3.19=3.34 + log c(NO2⁻)/c(HNO2)
</span><span>3.19 - 3.34 = log c(NO2⁻)/c(HNO2)
-0.15 = log c(NO2⁻)/c(HNO2)
c(NO2⁻)/c(HNO2) = 10⁰¹⁵ = 1.41
</span>
Answer:
1500 cubic centimeters or cm^3
Explanation:
1 liter is 1000 cm^3
move the decimal 3 places to right
Answer:
its the first one in the 3p section mf
Explanation:
The number of molecules of oxygen in the cylinder is 6.02×1023 molecules
Data obtained from the question
Number of mole of oxygen = 1 mole
Number of molecule of oxygen =?
From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02×1023 molecules. This implies that 1 mole of oxygen contains 6.02×1023 molecules.
Since the cylinder contains 1 mole of oxygen, then the number of molecules of oxygen present in the cylinder is 6.02×1023 molecules.
Hydrogen peroxide decomposes to yield water and oxygen gas
That is; H2O2 (l) = H2O (l) + O2(g)
The standard heat of formation; H2O2 (l) = -187.6 kJ/mol; H2O(l) = -285.8 kJ/mol
1 mole of hydrogen peroxide contains 34 g
Thus, 5.4 g contains 5.4/34 = 0.1588 moles
The moles of water produced will also be equivalent to 0.1588 moles
Heat = heat of formation of product - reactant
Therefore; Heat = (0.1588 moles × -285,8 )- (0.1588× -187.6)
= -15.594 kJ
