HBr and HF are both monoprotic Arrhenius acids—that is, in aqueous solution, they dissociate and ionize to give hydrogen ions. A strong acid ionizes completely; a weak acid ionizes partially.
In this case, HBr, being a strong acid, would ionize completely in water to yield H+ and Br- ions. However, HF, being a weak acid, would ionize only to a limited extent: some of the HF molecules will ionize into H+ and F- ions, but most of the HF will remain undissociated.
pH is, by definition, a measurement of the concentration of hydrogen ions in solution (pH = -log[H+]). A higher concentration of hydrogen ions gives a lower pH, while a lower concentration of hydrogen ions gives a higher pH. At 25 °C, a pH of 7 indicates a neutral solution; a pH less than 7 indicates an acidic solution; and a pH greater than 7 indicates a basic solution.
If we have equal concentrations of HBr and HF, then the HBr solution will have a greater concentration of hydrogen ions in solution than the HF solution. Consequently, the pH of the HBr solution will be less than the pH of the HF solution.
Choice A is incorrect: Strong acids like HBr dissociate completely, not partially.
Choice B is incorrect: While the initial concentration of HBr and HF are the same, the H+ concentration in the HBr solution is greater. Since pH is a function of H+ concentration, the pH of the two solutions cannot be the same.
Choice C is correct: A greater H+ concentration gives a lower pH value. The HBr solution has the greater H+ concentration. Thus, the pH of the HBr solution would be less than that of the HF solution.
Choice D is incorrect for the reason why choice C is correct.
Answer:
Explanation:
Convergent boundaries: where two plates are colliding. Subduction zones occur when one or both of the tectonic plates are composed of oceanic crust. ...
Divergent boundaries – where two plates are moving apart. ...
Transform boundaries – where plates slide passed each other.
Skuwel converter
Trust converter
Gear converter
Trigger converter
Hope it helps
Answer:
0.725 mol
Explanation:
Moles are calculated as the given mass divided by the molecular mass.
i.e. ,
moles = ( mass / molecular mass )
since,
mass of KNO₃ = 58.6 g ( given )
Molecular mass of KNO₃ = 101 g / mol
Therefore,
moles of KNO₃ = 58.6 g / 101 g / mol
moles of KNO₃ = 0.58 mol
From the balanced reaction ,
4 KNO₃ (s) ---> 2K₂O (s) + 2N₂ (g) + 5O₂ (g)
By the decomposition of 4 mol of KNO₃ , 5 mol of O₂ are formed ,
hence, unitary method is used as,
1 mol of KNO₃ gives 5 / 4 mol O₂
Therefore,
0.58 mol of KNO₃ , gives , 5 / 4 * 0.58 mol of O₂
Solving,
0.58 mol of KNO₃ , gives , 0.725 mol of O₂
Therefore,
58.6g of KNO₃ gives 0.725 mol of O₂.
