Question

Mr (H3PO4) = Mr (Na₂ SiO3) = Mr (K ₂ SO4) = Mr (Mg(OH)2 = Mr (Na NO3)= Mr (Cr (OH)3 =​

Answer 1

Відповідь:

Mr (H3PO4) =1*3+31+16*4=98

Mr (Na₂ SiO3) =23*2+28+16*3=122

Mr (K ₂ SO4) =39*2+32+16*4=174

Mr (Mg(OH)2 =24+(16+1)*2=58

Mr (Na NO3)=23+14+16*3=85

Mr (Cr (OH)3 =​52+(1+16)*3=103

Пояснення:

Answer 2

To calculate the molar mass (Mr) of a compound, we need to consider the atomic masses of the elements involved. Here are the molar masses of the compounds you mentioned:

1. Mr(H3PO4):

   • H (hydrogen) atomic mass = 1 g/mol
   • P (phosphorus) atomic mass = 31 g/mol
   • O (oxygen) atomic mass = 16 g/mol Calculating the molar mass: Mr(H3PO4) = (3 * H) + P + (4 * O) = (3 * 1) + 31 + (4 * 16) = 98 g/mol

2. Mr(Na2SiO3):

   • Na (sodium) atomic mass = 23 g/mol
   • Si (silicon) atomic mass = 28 g/mol
   • O (oxygen) atomic mass = 16 g/mol Calculating the molar mass: Mr(Na2SiO3) = (2 * Na) + Si + (3 * O) = (2 * 23) + 28 + (3 * 16) = 122 g/mol

3. Mr(K2SO4):

   • K (potassium) atomic mass = 39 g/mol
   • S (sulfur) atomic mass = 32 g/mol
   • O (oxygen) atomic mass = 16 g/mol Calculating the molar mass: Mr(K2SO4) = (2 * K) + S + (4 * O) = (2 * 39) + 32 + (4 * 16) = 174 g/mol

4. Mr(Mg(OH)2):

   • Mg (magnesium) atomic mass = 24 g/mol
   • O (oxygen) atomic mass = 16 g/mol
   • H (hydrogen) atomic mass = 1 g/mol Calculating the molar mass: Mr(Mg(OH)2) = Mg + (2 * O) + (2 * H) = 24 + (2 * 16) + (2 * 1) = 58 g/mol

5. Mr(NaNO3):

   • Na (sodium) atomic mass = 23 g/mol
   • N (nitrogen) atomic mass = 14 g/mol
   • O (oxygen) atomic mass = 16 g/mol Calculating the molar mass: Mr(NaNO3) = Na + N + (3 * O) = 23 + 14 + (3 * 16) = 85 g/mol

6. Mr(Cr(OH)3):

   • Cr (chromium) atomic mass = 52 g/mol
   • O (oxygen) atomic mass = 16 g/mol
   • H (hydrogen) atomic mass = 1 g/mol Calculating the molar mass: Mr(Cr(OH)3) = Cr + (3 * O) + (3 * H) = 52 + (3 * 16) + (3 * 1) = 104 g/mol

Please note that these values are approximate and may vary slightly depending on the isotopic composition of the elements.