Senior 1 Chemistry Question The state of aggregation of matter

, p, v, t are all the same, then the mass ratio of matter is n (oxygen): n (hydrogen) = 1:1, so the mass ratio of the two gases m (oxygen):

m (hydrogen) = m (hydrogen): m (oxygen) = 1:16, density = m v density ratio (oxygen):

Hydrogen) = m (oxygen): m (hydrogen) = 1:16

2.Because it is under standard conditions, the mass of the gas mixture n (mixed) = v v = so the relative molecular weight of the gas mixture is m (mixed gas) = m n The mass ratio of methane to carbon monoxide can be calculated according to the cross method. ch4

m (mixed) co anyway is the main requirement to solve the specific cross method I don't remember reading it I haven't reviewed the knowledge in high school for a long time I forgot it hehe.

1.Small ,,, m, nna m, mm nna

27 g mol (according to.

Relative atomic mass.

ratio 8:9, and can react with sulfuric acid to produce hydrogen, resulting in magnesium and aluminum) Both equations are reacted by volume of 2:1, 1) so it doesn't matter.

Gas mixtures. What is the ratio, 15L of oxygen has 10L left, then the remaining 5L of gas is CO2, so V (carbon monoxide) = 5L, V (hydrogen) = 5L

Hello! Remember a formula. pv=n

RT has some more derivation, and it's OK

Finish. Molar mass m=na*m

m is the mass of a molecule or atom.

When in doubt, please ask.

Listen well in class, these questions are not difficult at all.

1.The volume of the gas does not change before and after the reaction, so the total volume of the product is still 672ml, the density is, and the total mass of the product is. The total mass of the reactants is also and the mass of oxygen is , so the mass of xy2 is.

2. XY2 reacts with oxygen according to the amount of the substance 1:3, so the amount of the substance of XY2 is, and its molar mass is.

3. If the mass ratio of x and y is 3:16, then the molar mass of x is 3a, then 3a+16a=76, a=4So the molar mass of x is 12g mol and x is the carbon element.

The molar mass of y is 32g mol, and y is the sulfur element. So the chemical formula of XY2 is CS2

[Idea analysis] is based on the equation calculation of oxygen.

Problem solving process] Let the amount of XO2 formed by the reaction be x molxy2(l)+3o2(g)=xo2(g)+2yo2(g)1 3 1 2x 3x x 2x(1)O2 The amount of the substance is 3x, and the amount of total matter on the right side of the equation is 3x, because they are all gases, so the volume of O2 is 627ml

2) The molar mass of xy2 is conserved according to the mass, m(xo2) + m(yo2)-m(o2)] n(xy2)m(xo2) + m(yo2) can be calculated by volume multiplied by density, m(o2) can be calculated by multiplying the amount of oxygen by its molar mass m(xy2) = 76

3) m(x)=3 (3+16) 76=12, m(y)=1 2 16 (3+16) 76=32, so x is carbon and y is sulfur.

Question 1: The molar mass of hydrogen (m(h2)) is 2g mol, and the molar mass of O2 (m(O2)) is 32g mol. Under standard conditions, hydrogen and oxygen, the molar volume of gas is both.

Density = mass sock volume = m vm. Ratio of density of hydrogen to oxygen = m(h2) m(o2) = 2 32 = 1 16

Question 2: Memorize the equation of state for a formula gas: PV=NRT.

P is the pressure, V is the volume of the gas, N is the amount of matter, R is the constant of destruction, and T is the temperature. Now at the same temperature and pressure, with the same volume, the ratio of the amount of hydrogen to oxygen is 1:1

Let the mass of oxygen be x, and m(h2)= is known. Therefore, according to n=m m, the column equation::x 32=1:

1 gives x=

Answer: B

Analysis: The colloidal particles in Fe(OH)3 colloidal are positively charged, and it is necessary to add colloidal particles with negative charge, such as and electrolyte solution, such as , to make the colloidal sink together.

Use the elimination method to do, adding distilled water will only make its concentration smaller, so there are 5 do not choose, iron hydroxide is alkaline, silicic acid is acidic, and the neutralization reaction will occur together, and 1 is not selected.