Chapter 1 - Matter: Its Properties and Measurement - Example 1-4 - Using Percent as a Conversion Factor - Page 17: Practice Example A

1.8kg

Using dimensional analysis, the mass of ethanol can be found. mass = $25L (from gasohol)$ $\times$ $\frac{1000mL}{1L} \times \frac{0.71g (from gasohol)}{1mL (from gasohol)} \times \frac{10g (from ethanol)}{100g (from gasohol)} \times \frac{1kg (from ethanol)}{1000g (from ethanol)}$ Note: the $\frac{1000mL}{1L}$ and $\frac{1kg (from ethanol)}{1000g (from ethanol)}$ cancels out to equal 1. So the above equation will come to 1.8kg.