#### 621. A scientist has a solution containing 5 grams of salt dissolved in 95 grams of water. She adds another 10 grams of salt and 15 grams of water. What is the new concentration of salt in the solution as a percentage?
["### Understanding Salt Concentration: A Scientific Solution Update", "When studying solutions in chemistry, one key concept is concentration—specifically, the percentage of solute (salt) in a given amount of solvent (water). A recent calculation illustrates how to determine the new concentration after modifying a saltwater solution. Let’s break down the problem step-by-step to find the salt concentration as a percentage after the scientist adds more salt and water.", "---", "#### Step 1: Initial Solution Composition", "Initially, the scientist prepares a solution with:\n- 5 grams of salt\n- 95 grams of water (solvent)", "Total initial solution mass = 5 g salt + 95 g water = 100 grams", "The initial salt concentration is calculated as:\n[\n\ ext{Initial concentration} = \left( \frac{\ ext{mass of salt}}{\ ext{total solution mass}} \right) \ imes 100 = \left( \frac{5}{100} \right) \ imes 100 = 5%\n]", "---", "#### Step 2: Adding More Salt and Water", "The scientist then modifies the solution by adding:\n- 10 grams of salt\n- 15 grams of water", "New total salt mass = 5 g (initial) + 10 g (added) = 15 grams\nNew total water mass = 95 g (initial) + 15 g (added) = 110 grams\nNew total solution mass = 15 g salt + 110 g water = 125 grams", "---", "#### Step 3: Calculating Final Concentration", "Now, compute the new concentration as a percentage:\n[\n\ ext{New concentration} = \left( \frac{15, \ ext{g salt}}{125, \ ext{g total solution}} \right) \ imes 100 = 12%\n]", "---", "### Why This Matters: Salt Concentration in Real Applications", "Understanding concentration changes is essential in fields such as medicine, food science, environmental studies, and industrial processing. This example helps visualize how adding even small amounts of salt can significantly alter the result, which is vital for accurate formulation and safety—especially when precise salt levels are required.", "---", "### Summary", "- Start: 5 g salt in 100 g total (5% concentration)\n- Add: 10 g salt + 15 g water\n- New total: 15 g salt + 125 g solution\n- Final concentration: 12% salt by mass", "This simple yet powerful calculation demonstrates how to track solute-solvent ratios and reflects why concentration measurements are fundamental in chemistry and applied sciences.", "---", "Keywords: salt concentration, solution calculation, chemistry education, 5g salt, 95g water, adding salt, water dilution, percentage concentration, scientific solution study\nMeta description: Learn how to calculate salt concentration in a solution by updating initial values—step-by-step with a real-world example. Ideal for students and scientists tracking solute concentrations."]
