Question

M(SiO2)=30г W(прим.)=3% m(Si)-? SiO2+Mg->

Answer 1

Дано:

m'(SiO2)=30г

ω(прим.)=3%

m(Si)-?

Решение.

m(SiO2) = 30 г - 30 г*0,03 = 29,1 г

M(SiO2) = 60 г/моль

n(SiO2) = 29,1 г/60 г/моль = 0,485 моль

SiO2 + 2Mg = 2MgO + Si

Из УХР видно, что n(Si)=n(SiO2) = 0,485 моль

M(Si) = 28 г/моль

m(Si) = n*M = 0.485 моль*28 г/моль = 13,58 г

Ответ: 13,58 г

Answer 2

To find the mass of silicon (Si) produced when SiO2 reacts with Mg, we first need to balance the chemical equation:

SiO2 + Mg → Si + MgO

The balanced equation indicates that 1 mole of SiO2 reacts with 1 mole of Mg to produce 1 mole of Si and 1 mole of MgO.

Step 1: Calculate the molar mass of SiO2 (Molar mass of Si = 28.09 g/mol, Molar mass of O = 16.00 g/mol): M(SiO2) = (1 × M(Si)) + (2 × M(O)) M(SiO2) = (1 × 28.09 g/mol) + (2 × 16.00 g/mol) M(SiO2) = 60.09 g/mol

Step 2: Calculate the mass of SiO2 reacting (W(прим.)): W(прим.) = 3% (which means 3 g of SiO2 is present)

Step 3: Calculate the number of moles of SiO2 (n(SiO2)): n(SiO2) = W(прим.) / M(SiO2) n(SiO2) = 3 g / 60.09 g/mol n(SiO2) ≈ 0.0499 moles

Step 4: Since 1 mole of SiO2 produces 1 mole of Si, the number of moles of Si (n(Si)) produced will be the same as n(SiO2):

n(Si) ≈ 0.0499 moles

Step 5: Calculate the mass of Si (m(Si)): m(Si) = n(Si) × M(Si) m(Si) = 0.0499 moles × 28.09 g/mol m(Si) ≈ 1.402 g

So, approximately 1.402 grams of silicon (Si) will be produced when 3 grams of SiO2 reacts with magnesium (Mg).