Answer:
heated test tube in cold water
It is observed that when magnesium reacts with hydrochloric acid, it produces visible bubbles of hydrogen gas.
A vigorous reaction will occur giving rise of heat as it is an exothermic reaction. If heat is applied then it should be more vigorous.
Reaction is as follows:
Mg(s) + HCl (aq) --> MgCl2 (aq) + H2(g)
Magnesium reacts easily with HCl to produce H2 gas and magnesium ions, Mg2+, and heat. The reaction is exothermic, so it heats up quickly.
Mg(s) + HCl (aq) --> MgCl2(aq) + H2(g)
The net ionic equation :
Mg(s) + 2H+ --> Mg2 + H2(g)
If water is removed from the solution then white crystals of Mgcl2 is obtained.
Or in simple words,
2Mg + 2HCl -> 2Mg+ + 2Cl- + H2(gas)
The magnesium is attacked by the hydrochloric acid resulting in the magnesium dissolving into the solution resulting in a solution of magnesium chloride in hydrochloric acid and the production of hydrogen gas.
Learn more about magnesium here : brainly.com/question/5759562
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Assuming that the initial pH is pHi.
The initial concentration of [OH-] is
[OH]- = 10^(14 - pHi)
Since half of the Na2HPO4 is neutralized, the concentration of [OH-] will be reduced to half. The new pH will be
[OH-]/2 = 10^(14 - pHi)/2 = 10^(14 - pH)
14 - pHi - log 2 = 14 - pH
In terms of pHi,
pH = pHi + log 2
Answer:
30284.88J
Explanation:
c=mCtetha
c=257×2.4×49.1
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