Question

1. Mr (KBr) = 2. Mr (Al (OH) 3) =3. Mr (Ca3 (PO4) 2) =Все задачи по химии!!!Помогите пожалуйста, дам 20 балов!!!​

Answer 1

Ar - атомная масса

Ответ:

Mr(KBr) = Ar(K)+Ar(Br) = 39+80 = 119

Mr(Al(OH)3) = Ar(Al)+Ar(H)*3+Ar(O)*3 = 27+1*3+16*3 = 78

Mr(Ca3(PO4)2) = Ar(Ca)*3+Ar(P)*2+Ar(O)*8 = 40*3+31*2+16*8 = 310

Answer 2

Chemical Formulas and Molar Mass

To answer your question, let's break down the chemical formulas and calculate the molar mass for each compound.

1. Mr (KBr): - The chemical formula KBr represents potassium bromide. - To calculate the molar mass of KBr, we need to consider the atomic masses of potassium (K) and bromine (Br). - The atomic mass of potassium (K) is approximately 39.10 g/mol, and the atomic mass of bromine (Br) is approximately 79.90 g/mol. - Therefore, the molar mass of KBr is calculated as follows: ``` Molar mass of KBr = (atomic mass of K) + (atomic mass of Br) = 39.10 g/mol + 79.90 g/mol = 119.00 g/mol ``` - So, the molar mass of potassium bromide (KBr) is approximately 119.00 g/mol.

2. Mr (Al(OH)3): - The chemical formula Al(OH)3 represents aluminum hydroxide. - To calculate the molar mass of Al(OH)3, we need to consider the atomic masses of aluminum (Al), oxygen (O), and hydrogen (H). - The atomic mass of aluminum (Al) is approximately 26.98 g/mol, the atomic mass of oxygen (O) is approximately 16.00 g/mol, and the atomic mass of hydrogen (H) is approximately 1.01 g/mol. - Therefore, the molar mass of Al(OH)3 is calculated as follows: ``` Molar mass of Al(OH)3 = (atomic mass of Al) + 3 * (atomic mass of O) + 3 * (atomic mass of H) = 26.98 g/mol + 3 * 16.00 g/mol + 3 * 1.01 g/mol = 78.00 g/mol ``` - So, the molar mass of aluminum hydroxide (Al(OH)3) is approximately 78.00 g/mol.

3. Mr (Ca3(PO4)2): - The chemical formula Ca3(PO4)2 represents calcium phosphate. - To calculate the molar mass of Ca3(PO4)2, we need to consider the atomic masses of calcium (Ca), phosphorus (P), oxygen (O), and hydrogen (H). - The atomic mass of calcium (Ca) is approximately 40.08 g/mol, the atomic mass of phosphorus (P) is approximately 30.97 g/mol, the atomic mass of oxygen (O) is approximately 16.00 g/mol, and the atomic mass of hydrogen (H) is approximately 1.01 g/mol. - Therefore, the molar mass of Ca3(PO4)2 is calculated as follows: ``` Molar mass of Ca3(PO4)2 = 3 * (atomic mass of Ca) + 2 * (atomic mass of P) + 8 * (atomic mass of O) = 3 * 40.08 g/mol + 2 * 30.97 g/mol + 8 * 16.00 g/mol = 310.18 g/mol ``` - So, the molar mass of calcium phosphate (Ca3(PO4)2) is approximately 310.18 g/mol.

I hope this helps! Let me know if you have any further questions.