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Anonymous users2024-02-07Solution: The mass of sulfuric acid is 40g*
h2so4+cuo=cuso4+h2o
4g 8g so cuo quality 4g
CuSO4 mass fraction 8g (40g+4g)*100%=solution:HCl+AGnO3=AGCL+HNO3 So the mass fraction of hydrochloric acid is.
200g* So add water 292g-200g=92g solution: mg+2HCl=mgCl2+H2
So, the mass fraction of elemental magnesium is:
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Anonymous users2024-02-06Writing an answer to you is a disservice to you!
In the first question, you first calculate the mass of sulfuric acid in the sulfuric acid solution, let the mass of copper oxide be x, write the chemical formula of the reaction, write the relative atomic mass correspondingly, and then calculate it according to the ratio!
Divide the mass of copper sulphate by the mass of the solution and multiply it by one hundred percent!
The second question is to write the chemical formula of the reaction, set the hydrochloric acid mass to x, and note that it is not a hydrochloric acid solution! And then just work it out.
Question 3, write the chemical formula of the reaction, set the mass of magnesium to x, then calculate it, and divide it by 5 grams to change it to a percentage!
Calculation questions are generally like this, a child who scored 48 points in the chemistry test is very magical hand-typed!
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Anonymous users2024-02-05Writing an answer to you is a disservice to you!
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Anonymous users2024-02-04Solution: The mass of sulfuric acid is 40g*
h2so4+cuo=cuso4+h2o
4g 8g so cuo quality 4g
CuSO4 mass fraction 8g (40g+4g)*100%=solution:HCl+AGnO3=AGCL+HNO3 So the mass fraction of hydrochloric acid is.
200g* So add water 292g-200g=92g solution: mg+2HCl=mgCl2+H2
So, the mass fraction of elemental magnesium is:
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Anonymous users2024-02-031.Protosolute = 50 * 10% = 5
Present solute = 5 + 10 = 15 g
Mass fraction = 15 (50+10) = 25%.
Water can dissolve 36gnacl
The mass fraction of saturated NaCl is 36 136 = maximum) and then 15 grams of salt are added The mass of the solution is 50 + 15 = 65g mass fraction = (5 + 15) 65 = >, so it is only possible that the excess part is undissolved and is solid.
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Anonymous users2024-02-021) 50 grams of 10% salt water contains 50 * 10% = 5 grams of salt The solubility of salt at 20 degrees Celsius is 36 grams and 18-5 = 13 grams It can be seen that 10 grams of salt is all dissolved Mass fraction 15 60 * 100% = 25%.
2) It can also dissolve 13 grams of salt in the solution at this time, and the mass fraction of table salt in the solution is (13 + 5) (50 + 13) * 100% =
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Anonymous users2024-02-01Analysis: g=10n kg
1) The pressure of water on the bottom of the teapot p= water gh=1000kg m *10n kg*
The pressure of water on the bottom of the teapot f = ps = 40 * 10 -4 m = (2) the pressure of the teapot on the table top f'=g1+g2=(Since the area of the bottom of the teapot is smaller than the area of the table top and the teapot is placed on the table **, the stressed area is the area of the bottom of the teapot.)
The pressure of the teapot on the tabletop p'=f'/s =10n/ 40*10^-4m²=2500pa
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