Classify each of the following mixtures as homogeneous or heterogeneous:
a. nonfat milk
b. chocolate-chip ice cream
c. gasoline
d. peanut butter sandwich
e. cranberry juice
Indicate whether each of the following describes a gas, a liquid, or a solid:
a. Lemonade has a definite volume but takes the shape of its container.
b. The particles in a tank of oxygen are very far apart.
c. Helium occupies the entire volume of a balloon. °F 3.
Solve the following temperature conversions:
a. 25 °C =
b. 155 °C =
c. -25 °F =
d. 224 K =
e. 145 °C =
The Correct Answer and Explanation is :
Let’s break down each part of your question step by step.
1. Classifying mixtures as homogeneous or heterogeneous:
- a. Nonfat milk – Homogeneous
Nonfat milk is considered homogeneous because the water, proteins, and other components are evenly distributed and cannot be distinguished by the naked eye. It appears uniform throughout. - b. Chocolate-chip ice cream – Heterogeneous
Chocolate-chip ice cream is a heterogeneous mixture. You can see and separate the chocolate chips from the ice cream, and there is no uniform distribution of particles throughout. - c. Gasoline – Homogeneous
Gasoline is a homogeneous mixture, even though it consists of many hydrocarbons. These components are thoroughly mixed, so it looks uniform to the naked eye. - d. Peanut butter sandwich – Heterogeneous
A peanut butter sandwich is a heterogeneous mixture because you can see and distinguish the peanut butter from the bread, and the distribution is not uniform. - e. Cranberry juice – Homogeneous (if filtered) or Heterogeneous (if unfiltered)
Cranberry juice can be homogeneous if it is filtered and contains a uniform liquid. However, if it contains pulp and pieces of fruit, it would be heterogeneous.
2. Indicating the state (gas, liquid, or solid):
- a. Lemonade has a definite volume but takes the shape of its container.
This describes a liquid, because liquids have a definite volume but no definite shape. They conform to the shape of their container. - b. The particles in a tank of oxygen are very far apart.
This describes a gas, because in gases, the particles are far apart and move freely, filling the entire space available. - c. Helium occupies the entire volume of a balloon.
This describes a gas, as helium will expand to fill the volume of the balloon, and gases have neither definite shape nor volume.
3. Temperature conversions:
To convert between temperature scales, we need to use the following formulas:
- From Celsius (°C) to Fahrenheit (°F):
[
°F = (°C \times \frac{9}{5}) + 32
] - From Celsius (°C) to Kelvin (K):
[
K = °C + 273.15
] - From Fahrenheit (°F) to Celsius (°C):
[
°C = (°F – 32) \times \frac{5}{9}
] - From Kelvin (K) to Celsius (°C):
[
°C = K – 273.15
]
a. 25°C to Fahrenheit:
[
°F = (25 \times \frac{9}{5}) + 32 = 77°F
]
b. 155°C to Fahrenheit:
[
°F = (155 \times \frac{9}{5}) + 32 = 311°F
]
c. -25°F to Celsius:
[
°C = (-25 – 32) \times \frac{5}{9} = -31.67°C
]
d. 224 K to Celsius:
[
°C = 224 – 273.15 = -49.15°C
]
e. 145°C to Kelvin:
[
K = 145 + 273.15 = 418.15K
]
Explanation:
- Temperature conversions require an understanding of how the scales relate to each other. Celsius and Kelvin are often used in scientific contexts, while Fahrenheit is more common in everyday use in the United States.
- The Celsius and Kelvin scales are directly related, with the Kelvin scale simply starting at absolute zero (0 K = -273.15°C). Fahrenheit, on the other hand, has a different scale and is often used for weather and everyday temperature measurements, especially in countries like the United States. The conversion formulas allow us to switch between these different temperature systems easily.