Question

Количество вещества кислорода,которую присоединяет кальций кол.вещества 0.2 состовляета)0.1 мольб)0.2 мольв)0.4 моль(и объяснение как считать)Металические свойства элементов возрастают в рядеа)Po,Te,Se,S,Oб)N,P,As,Sbв)Li,Na,K,Rb,CsЛатунь состовляет 68% меди и 32% цинка.Какие массы меди и цинка содержатся в 200г сплава?а) 168г и 32 гб)150 г и 50 гв)136 г и 64 г

Answer 1

1)  ответ А

0.2 моль    х

2Ca+        O2=2CaO

2моль    1 моль

х=(0.2 *1) : 2= 0.1

 

2) В

 

3)  масса цинка=200г *0.32=64 г

     масса меди= 200г*0.68=136 г

 

ответ: В

Answer 2

Calculation of the Amount of Oxygen Calcium Binds

To calculate the amount of oxygen that calcium binds, we need to determine the molar ratio between calcium and oxygen in the compound. The molar ratio is determined by the coefficients in the balanced chemical equation.

Given that the amount of the compound is 0.2 moles, we can calculate the amount of oxygen using the molar ratio.

The molar ratio between calcium and oxygen can be determined from the chemical formula of the compound. However, the chemical formula is not provided in the question. Therefore, we cannot accurately determine the molar ratio and calculate the amount of oxygen without additional information.

Please provide the chemical formula of the compound so that we can accurately calculate the amount of oxygen calcium binds.

Metallic Properties of Elements

The metallic properties of elements can be determined by their position in the periodic table. Generally, metallic properties increase as you move from right to left across a period and from top to bottom within a group.

Let's analyze the given options:

a) Po, Te, Se, S, O: This is a decreasing order of metallic properties. Oxygen (O) is a nonmetal, while the other elements in the list are metalloids or metals.

b) N, P, As, Sb: This is also a decreasing order of metallic properties. Nitrogen (N) is a nonmetal, while the other elements in the list are metalloids or metals.

c) Li, Na, K, Rb, Cs: This is an increasing order of metallic properties. Lithium (Li) is the least metallic, while cesium (Cs) is the most metallic.

Therefore, the correct answer is c) Li, Na, K, Rb, Cs.

Calculation of Copper and Zinc Masses in Brass Alloy

To calculate the masses of copper and zinc in the brass alloy, we need to determine the percentages of copper and zinc in the alloy and then use those percentages to calculate the masses.

Given that the brass alloy consists of 68% copper and 32% zinc, we can calculate the masses using the following steps:

1. Calculate the mass of copper: - Percentage of copper = 68% - Mass of copper = (Percentage of copper / 100) * Total mass of the alloy - Mass of copper = (68 / 100) * 200 g

2. Calculate the mass of zinc: - Percentage of zinc = 32% - Mass of zinc = (Percentage of zinc / 100) * Total mass of the alloy - Mass of zinc = (32 / 100) * 200 g

Calculating the values:

1. Mass of copper = (68 / 100) * 200 g = 136 g 2. Mass of zinc = (32 / 100) * 200 g = 64 g

Therefore, the masses of copper and zinc in the 200 g brass alloy are 136 g and 64 g, respectively.