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Uhm , Alkalis are just bases who react with water. In titration we use water also , so we need bases that react with water , and such bases are alkalis.
Alkalis are a type of bases.
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Earth is the right distance from the sun. It’s protected from harmful solar radiation by its magnetic field and the atmosphere keeps it warm. Earth contains the right chemical ingredients to sustain life such as H2O (water) and C (carbon)
To find for the oxidizing agent, first let us write the
half reactions of this complete chemical reaction:
Ca = Ca2+ + 2e- <span>
2 H+ + 2e- = H2</span>
The oxidizing agent
would be the substance of the element that is reduced. We know that an element
is reduced when an electron is added to it. In this case, the element being
reduced is H. Therefore the oxidizing agent is HNO3.
Answer:
<span>HNO3</span>
The balanced equation for the reaction is as follows;
Ca(OH)₂ + 2HBr --> CaBr₂ + 2H₂O
stoichiometry of Ca(OH)₂ to HBr is 1:2
number of Ca(OH)₂ moles reacted - 0.10 mol/L x 0.1000 L = 0.010 mol
Number of HBr moles added - 0.10 mol/L x 0.4000 = 0.040 mol
1 mol of Ca(OH)₂ needs 2 mol of HBr for neutralisation
therefore 0.010 mol of Ca(OH)₂ needs - 0.010 x 2 = 0.020 mol of HBr to be neutralised
but 0.040 mol of HBr has been added therefore number of moles of HBr in excess - 0.040 - 0.020 = 0.020 mol
then pH of the medium can be calculated using the excess H⁺ ions
HBr is a strong acid therefore complete ionization
[HBr] = [H⁺]
[H⁺] = 0.020 mol / (100.0 + 400.0 mL)
= 0.020 mol / 0.5 L
= 0.040 mol/L
pH = -log[H⁺]
pH = - log [0.040 M]
pH = 1.40
pH of the medium is 1.40
