4. Solve the following problems. a) Liquid Mercury meta is poured into a graduated cylinder that holds exactly 22.5 mL The mercury used to fill the cylinder weighs 306.0 g. From this information, calculate the density of mercury. (4 marks) b) What is the mass of the ethyl alcohol that exactly fills a 200.0mL container? The density of ethyl alcohol is 0.789g/mL 5. Explain what the flow rate of a liquid is. Why do we need to know the flow rate of a liquid?Use an example in your answer. (3 marks) 6. Do all liquids have the same viscosity?Using examples, explain. (3 marks)

### 4. Solve the following problems:<br /><br />#### a) **Calculate the density of mercury:**<br /><br />The formula for density is:<br />\[<br />\text{Density} = \frac{\text{Mass}}{\text{Volume}}<br />\]<br /><br />Given:<br />- Mass of mercury, \( m = 306.0 \, \text{g} \)<br />- Volume of mercury, \( V = 22.5 \, \text{mL} \)<br /><br />Substitute the values into the formula:<br />\[<br />\text{Density} = \frac{306.0 \, \text{g}}{22.5 \, \text{mL}}<br />\]<br />\[<br />\text{Density} = 13.6 \, \text{g/mL}<br />\]<br /><br />**Answer:** The density of mercury is **13.6 g/mL**.<br /><br />---<br /><br />#### b) **Calculate the mass of ethyl alcohol:**<br /><br />The formula for mass is:<br />\[<br />\text{Mass} = \text{Density} \times \text{Volume}<br />\]<br /><br />Given:<br />- Density of ethyl alcohol, \( \rho = 0.789 \, \text{g/mL} \)<br />- Volume of ethyl alcohol, \( V = 200.0 \, \text{mL} \)<br /><br />Substitute the values into the formula:<br />\[<br />\text{Mass} = 0.789 \, \text{g/mL} \times 200.0 \, \text{mL}<br />\]<br />\[<br />\text{Mass} = 157.8 \, \text{g}<br />\]<br /><br />**Answer:** The mass of ethyl alcohol is **157.8 g**.<br /><br />---<br /><br />### 5. **Explain what the flow rate of a liquid is and why it is important:**<br /><br />The **flow rate** of a liquid refers to the volume of liquid that passes through a specific point or area per unit of time. It is typically measured in units such as liters per second (L/s) or milliliters per minute (mL/min).<br /><br />**Why do we need to know the flow rate?**<br />Knowing the flow rate is essential in various applications to ensure proper functioning and efficiency. For example:<br />- In medical settings, the flow rate of intravenous fluids must be carefully controlled to deliver medication at the correct speed.<br />- In industrial processes, the flow rate of liquids like oil or water needs to be monitored to maintain production efficiency and safety.<br /><br />**Example:**<br />In a water treatment plant, the flow rate of water being filtered must be regulated to ensure that contaminants are removed effectively while maintaining an adequate supply of clean water.<br /><br />---<br /><br />### 6. **Do all liquids have the same viscosity?**<br /><br />No, all liquids do not have the same viscosity. **Viscosity** is a measure of a liquid's resistance to flow. Different liquids have different viscosities depending on their molecular structure and intermolecular forces.<br /><br />**Examples:**<br />- **Low-viscosity liquids:** Water and ethanol flow easily because they have low resistance to flow.<br />- **High-viscosity liquids:** Honey and motor oil flow more slowly because they have higher resistance to flow.<br /><br />**Explanation:**<br />Viscosity depends on factors such as temperature and the strength of intermolecular forces. For instance, heating honey reduces its viscosity, making it flow more easily. This demonstrates that viscosity varies not only between liquids but also with changes in conditions like temperature.