mg(k2 co3 )=250г m(Mgco3)=16,8г w(k2co3)-?

To calculate the mass fraction (\( w \)) of potassium carbonate (\( K_2CO_3 \)) in the given mixture, we need to find the mass of potassium carbonate in relation to the total mass of the mixture.

Let's denote:

• \( m(K_2CO_3) \) as the mass of potassium carbonate,
• \( m(MgCO_3) = 16.8 \) g as the mass of magnesium carbonate,
• \( m(K_2CO_3) \) is what we need to calculate.

The total mass given is \( m(K_2CO_3) + m(MgCO_3) = 250 \) g.

From this, we can deduce: \[ m(K_2CO_3) + 16.8 = 250 \] \[ m(K_2CO_3) = 250 - 16.8 = 233.2 \text{ g} \]

Now that we have the mass of \( K_2CO_3 \), we can calculate the mass fraction \( w(K_2CO_3) \): \[ w(K_2CO_3) = \frac{m(K_2CO_3)}{m(K_2CO_3) + m(MgCO_3)} = \frac{233.2}{250} \]

Now, calculate \( w(K_2CO_3) \): \[ w(K_2CO_3) = \frac{233.2}{250} \] \[ w(K_2CO_3) = 0.9328 \]

To express it as a percentage: \[ w(K_2CO_3) \times 100 = 93.28\% \]

Thus, the mass fraction of potassium carbonate (\( w(K_2CO_3) \)) in the mixture is approximately 93.28%.