Diffusion and Osmosis Worksheet sovspg - Diffusion and Osmosis ... - Free Printable

Let's go through the Diffusion and Osmosis Worksheet step by step, explaining each answer and ensuring clarity.

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1. How are the molecules moving in the examples below? Write OSMOSIS or DIFFUSION.

a. The student sitting next to you just came from gym class and forgot to shower and you can tell.
✔ Diffusion
➡️ *Explanation:* The smell of sweat (molecules) spreads through the air from a high concentration (near the student) to a low concentration (around you). This is diffusion of gas molecules.

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b. After sitting in the bathtub for hours, your fingers start to look like prunes.
✔ Osmosis
➡️ *Explanation:* Water moves into the skin cells (which have a higher solute concentration than the bathwater), causing them to swell. This movement of water across a semi-permeable membrane is osmosis.

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c. The girl sitting two rows ahead of you put on too much perfume this morning.
✔ Diffusion
➡️ *Explanation:* Perfume molecules spread through the air from a high concentration (near her) to a lower concentration (around you). This is diffusion of volatile molecules.

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d. One way to get rid of slugs in your garden is to sprinkle salt on them, so they shrivel up.
✔ Osmosis
➡️ *Explanation:* Salt creates a hypertonic environment outside the slug. Water moves out of the slug’s cells into the surrounding area via osmosis, causing the cells to shrink and the slug to shrivel.

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e. Yum! Something smells good. The neighbors are cooking on the grill!
✔ Diffusion
➡️ *Explanation:* Food odor molecules diffuse through the air from the grill to your nose. This is diffusion of airborne particles.

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f. Gargling with salt water when you have a sore throat causes your swollen throat cells to shrink and feel better.
✔ Osmosis
➡️ *Explanation:* The salt water is hypertonic compared to the fluid inside your throat cells. Water leaves the cells via osmosis, reducing swelling.

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g. Oxygen molecules move from the air sacs in the lungs across the cell membranes into the blood.
✔ Diffusion
➡️ *Explanation:* Oxygen moves from an area of high concentration (in the alveoli) to an area of low concentration (in the blood). This is diffusion across membranes.

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2. Use arrows to indicate the direction of diffusion in each case below:

- A) Diagram shows more molecules outside the box than inside.
- ✔ Arrow points into the box (from outside to inside).
- ⬇️ *Why?* Molecules move from high to low concentration → from outside (high) to inside (low).

- B) Diagram shows fewer molecules inside the box than outside.
- ✔ Arrow points out of the box (from inside to outside).
- ⬇️ *Why?* Molecules move from high to low concentration → from inside (high) to outside (low).

> ✔️ These red arrows in your image are correct!

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3. For each situation, use an arrow to indicate net movement of sugar into or out of the cell.

We assume sugar can pass through the membrane.

#### Cell 1: Inside = 1% sugar, Outside = 5% sugar
- ✔ Arrow points into the cell (upward).
- ⬇️ *Why?* Sugar moves from high (outside: 5%) to low (inside: 1%) → into the cell.

#### Cell 2: Inside = 3% sugar, Outside = 1% sugar
- ✔ Arrow points out of the cell (downward).
- ⬇️ *Why?* Sugar moves from high (inside: 3%) to low (outside: 1%) → out of the cell.

#### Cell 3: Inside = 1% sugar, Outside = 1% sugar
- ✔ Arrow is double-headed (equal in both directions).
- ⬇️ *Why?* Equal concentrations → no net movement. Equilibrium.

> ✔️ Your red arrows are correct!

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4. Diffusion always causes particles to move from a region of ________ concentration to a region of ________ concentration.

✔ High → Low

➡️ *Explanation:* Diffusion is the passive movement of particles from areas of higher concentration to areas of lower concentration until equilibrium is reached.

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5. Does a cell use energy when molecules diffuse in or out of the cell?

✔ No

➡️ *Why?* Because diffusion is a passive process — it relies on the natural kinetic motion of particles and does not require cellular energy (ATP). It occurs spontaneously due to concentration gradients.

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✔ Summary of Answers:

| Question | Answer |
|--------|--------|
| 1a | Diffusion |
| 1b | Osmosis |
| 1c | Diffusion |
| 1d | Osmosis |
| 1e | Diffusion |
| 1f | Osmosis |
| 1g | Diffusion |
| 2A | Arrow into box |
| 2B | Arrow out of box |
| 3a | Arrow into cell (1% → 5%) |
| 3b | Arrow out of cell (3% → 1%) |
| 3c | Double-headed arrow (equilibrium) |
| 4 | High → Low |
| 5 | No – because diffusion is passive and doesn't require energy |

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All your answers (including the red annotations) are correct! Great job understanding diffusion and osmosis concepts. 🎉

Let me know if you'd like a diagram explanation or further breakdown!