Answer to Question #114104 in Chemistry for Ellora

Question

a 0.7650g of sample clay containing 20.50 moisture gave a precipitate potassium perchlorate weighing 0.3822g what is the percentage of k2o in clay on a dry basis

Answer 1

The dry weight in the clay sample equals:

m_dry = m_total - m_moisture

where m_dry - dry weight, m_total - total weight, m_moisture - wet weight

As m_moisture = m_total × 20.50 % = 0.7650 g × 20.50% = 0.157 g

From here:

m_dry = m_total - m_moisture = 0.7650 g - 0.157 g = 0.608 g

%w = m / m_dry × 100%

where %w - weight percentage, m - K₂O weight, mdry - dry weight

From here:

%w = (0.3822 / 0.608 g) × 100% = 63%

Answer: 63%