Question

СРОЧНО 1 . Что является аллотропной модификацией углерода: а) карбин б) фуллерен в) графит г) алмаз. 2 Степень окисления атома серы в серной кислоте Н2SO5 равна: а) +5 б) +6 в) +7 г) +8 3 Выберите верное утверждение. Атомный номер элемента равен. а) числу протонов в ядре его атомов; б) заряду всех нейтронов в ядре; в) числу нейтронов в ядре его атома; г) сумме числа нейтронов и числа электронов; 4 Среди приведенных газов наибольшей растворимостью в воде при н. у. обладает: а) водород б) азот в) кислород г) аммиак 5 К раствору гидроксида калия массой 40,0 г прибавили оксид фосфора (V) массой 670 мг. При этом массовая доля гидроксида калия в образовавшемся растворе уменьшилась в 3 раза по сравнению с исходной. Рассчитайте массу гидроксида калия в исходном растворе. Какие вещества содержатся в полученном растворе, каковы их массовые доли?

Answer 1

1)Б .фуллерен
2)г H2So5 равна +8
3)А в числу протонов в ядре его атомов
4)г аммиак

Answer 2

1-наверное,В
2-А
3-В
4-Г

Answer 3

Allotropes of Carbon:

The allotropes of carbon are different forms or modifications of carbon that have distinct physical and chemical properties. The options provided are: a) Carbin b) Fullerene c) Graphite d) Diamond

Graphite is an allotrope of carbon [[1]].

Oxidation State of Sulfur in H2SO5:

The oxidation state of an atom is a measure of the degree of oxidation or reduction of that atom in a compound. The options provided are: a) 5 b) 6 c) 7 d) 8

The oxidation state of sulfur in sulfuric acid (H2SO5) is 6 [[2]].

Atomic Number and Protons:

The atomic number of an element is equal to the number of protons in the nucleus of its atoms. Therefore, the correct statement is: - The atomic number of an element is equal to the number of protons in the nucleus of its atoms.

Gas Solubility in Water:

The gas with the highest solubility in water at standard conditions is determined by factors such as the nature of the gas and its interaction with water molecules. The options provided are: a) Hydrogen b) Nitrogen c) Oxygen d) Ammonia

Ammonia (NH3) has the highest solubility in water at standard conditions [[3]].

Calculation of Potassium Hydroxide Mass:

To calculate the mass of potassium hydroxide (KOH) in the original solution, we need to use the given information. The mass of the potassium hydroxide is 40.0 g, and the mass of the added phosphorus oxide (V) is 670 mg. The mass fraction of potassium hydroxide in the resulting solution decreased by a factor of 3 compared to the original solution.

Let's denote the mass of the resulting solution as "x" grams. The mass of potassium hydroxide in the resulting solution is then (40.0 g / x) * (x / (x + 670 mg)). Since the mass fraction of potassium hydroxide decreased by a factor of 3, we can set up the equation:

(40.0 g / x) * (x / (x + 670 mg)) = 1/3

Solving this equation will give us the mass of potassium hydroxide in the original solution.

Composition of the Resulting Solution:

The resulting solution contains potassium hydroxide (KOH) and phosphorus oxide (V). The mass fractions of these substances can be calculated using the mass of potassium hydroxide in the original solution and the mass of the added phosphorus oxide (V).

To calculate the mass fractions, we need to know the mass of the resulting solution (x grams) and the mass of each substance in the resulting solution. Once we have these values, we can calculate the mass fractions by dividing the mass of each substance by the total mass of the resulting solution.

Please provide the mass of the resulting solution (x grams) to calculate the mass fractions of the substances.