what mass of water must be added to 385g of formaldehyde to prepare a 35% of solution of formaldehyde…

what mass of water must be added to 385g of formaldehyde to prepare a 35% of solution of formaldehyde? (hint: 35% means 100g solution for 35g of solute; and solution = solute + solvent).\n1) 385g of water\n2) 1100g of water\n3) 715g of water\n4) 637.5g of water

what mass of water must be added to 385g of formaldehyde to prepare a 35% of solution of formaldehyde? (hint: 35% means 100g solution for 35g of solute; and solution = solute + solvent).\n1) 385g of water\n2) 1100g of water\n3) 715g of water\n4) 637.5g of water

Answer

Explanation:

Step1: Define variables

Let ( m_{\text{solution}} ) be the mass of the solution, ( m_{\text{solute}} = 385,\text{g} ) (formaldehyde), and the mass percentage of solute is ( 35% ). The formula for mass percentage is ( \text{Mass},% = \frac{m_{\text{solute}}}{m_{\text{solution}}} \times 100% ).

Step2: Calculate total solution mass

From ( 35% = \frac{385,\text{g}}{m_{\text{solution}}} \times 100% ), solve for ( m_{\text{solution}} ):
( m_{\text{solution}} = \frac{385,\text{g} \times 100%}{35%} = \frac{38500}{35} = 1100,\text{g} ).

Step3: Find mass of water (solvent)

Since ( m_{\text{solution}} = m_{\text{solute}} + m_{\text{solvent}} ), then ( m_{\text{solvent}} = m_{\text{solution}} - m_{\text{solute}} ).
Substitute values: ( m_{\text{solvent}} = 1100,\text{g} - 385,\text{g} = 715,\text{g} ).

Answer:

  1. 715g of water