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Anonymous users2024-02-15Let's write down the reaction first.
alcl3+naoh=naalo2+3nacl+2h2o...
alcl3+3naoh=al(oh)3↓+3nacl...
According to experiment 3 in the title, we can know that if B is less, the precipitation is more, so we can be sure that B is NaOH solution and A is ALCL3 solution.
According to to get a relation, 3NaOH al(OH)3 is to be calculated here using Experiment 3, because NaOH is insufficient, and the amount of precipitation is determined by NaOH.
al(oh)3=
It should be needed to get naoh according to the relation.
So we know the amount and concentration of NaOH substances.
The coefficient ratio of the reaction will also be equal to the ratio of concentrations.
So the amount of AlCl3 substance concentration should be.
3mol/l ÷3 =1mol/l
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Anonymous users2024-02-14From the experiment, it can be seen that the additional 40ml of solution B dissolves (i.e. mol) Al(OH)3, and the equation for this process is as follows:
Al(OH)3 + NaOH = Naalo2 + 2H2O, whereas this process uses NaOH 40ml
So its concentration c(NaOH) = =
Looking at the second experiment, we analyze the state of the current solution, there should be NaCl, Naalo2, Al(OH)3 in the solution, if there is X mol in AlCl3 in 120ml of AlCl3 solution, then the final NaCl should be 3x mol (chloride ion conservation), sodium ions should also have 3x mol, Al(Oh)3 has mol, so the sodium ion in Naalo2 should be (-3x), and the aluminum element should be (, And these two values are equal (because the ratio of the number of na and al in naalo2 is 1:1).
So- 3x = solution x = mol so its concentration c(alcl3) = =
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Anonymous users2024-02-13First of all, there must be NO2 in gas A, so solution B is nitric acid, solution B is dilute nitric acid, and gas B is NO.
Then look at C is a blue solution, so there is Cu2+, and the blind resistance is to dig the book of elemental C as Cu.
Because gas A and calcium hydroxide produce a white precipitate, the precipitate is CaCO3, gas A is CO2, and Chang Sankong is black solid A is carbon element.
So the answer is (1)c, nitric acid, cu. （2）no2，co2。（3）no，cu(no3)2
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