Answer:
The energy of the products is less than the energy of the reactants, so energy is released into the surrounding environment.
Answer:
The correct answer is - B. dissolving → evaporation filtration → crystallisation
Explanation:
The method of the preparation of a pure sample of copper(II) sulfate from dilute sulfuric acid and copper II oxide is given as follows:
step 1. Adding dilute sulfuric acid into a beaker. Using bunsen burner heat the beaker.
step 2. Adding the copper (II) oxide into the beaker and give it a little time at a time to the warm dilute sulfuric acid and stir
step 3. Filtering the mixture into an evaporating vessel to remove the excess copper (II) oxide and water from the filtrate.
Step 4. leave the rest filtrate to crystallize.
Copper (II) Oxide {CuO (s)} + Dilute Sulfuric Acid {H2SO4 (aq)} → Copper (II) Sulphate {CuSO4 (s)} + Water {H2O}
Answer:
Mendeleev had left the noble gases out of his periodic table.
Explanation:
Mendeleev's periodic table is pictured in the image attached to the question.
Mendeleev's table obviously lacked the noble gases. The reason for this grave omission is simple; the noble gases were not known as at the time when he formulated his periodic table. There weren't any known elements whose properties were similar to the properties of the noble gases. This would have lead him to suspect their existence.
Answer: (C) Vaporizing
Explanation:
Vaporization is the process in which the substance change the state of of liquid into the gas state.
The vaporization process require the largest input of the energy as when the state is in the solid state then, the solid substances contain the strong forces of the attraction and they require high energy to break these strong bonds.
For changing the liquid state into the gases state we require to overcome the surface tension and require enough energy for acquiring the vaporization state.
Therefore, option (C) is correct.
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