Chất này có trong nước.

Chất means substance, material, or sometimes chemical substance, depending on context.

In Chất này có trong nước, it most naturally means this substance.
This is a fairly common word in scientific, medical, or descriptive language.

Examples:

• chất độc = toxic substance / poison
• chất béo = fat
• chất hóa học = chemical substance

In Vietnamese, demonstratives like này (this) usually come after the noun.

So:

• chất này = this substance
• người này = this person
• cuốn sách này = this book

This is one of the most noticeable differences from English word order.

Here, có does not mean exactly have in the English sense. In this sentence, it means something more like:

• exists
• is present
• is found

So Chất này có trong nước means that this substance is present in water or is found in water.

Vietnamese often uses có in this broader existence/presence sense.

Compare:

• Tôi có tiền. = I have money.
• Trong phòng có một cái bàn. = There is a table in the room.
• Chất này có trong nước. = This substance is present in water.

Trong usually means in or inside.

So:

• trong nước = in water

In this sentence, có trong works together to mean to be in / to be found in / to be present in.

Vietnamese often does not need a verb like English to be in the same way.

English says:

• This substance is in water.

Vietnamese can express that idea without a direct equivalent of is:

• Chất này có trong nước.

This is very normal. Vietnamese grammar often relies on word order and context rather than adding a separate linking verb.

In this sentence, yes, nước is understood as water.

The word nước can also mean country/nation, so learners often notice that ambiguity. But in có trong nước, the meaning in water is the natural one.

Examples:

• uống nước = drink water
• nước Việt Nam = the country of Vietnam

Context tells you which meaning is intended.

The structure is:

Chất này + có + trong nước

You can think of it as:

• Chất này = this substance
• có = exists / is present
• trong nước = in water

So the whole sentence is literally something like:

This substance exists in water.

That is why a natural English translation is This substance is found in water or This substance is present in water.

You might hear or say Chất này ở trong nước, but it can sound a bit different.

• có trong nước usually means is found in water / is present in water
• ở trong nước more literally means is in water / is inside water

So có trong is often better when talking about a substance as something contained in or occurring in water, especially in scientific or descriptive contexts.

If you are describing location very literally, ở trong can work, but có trong is more natural for this kind of sentence.

Yes, it sounds somewhat neutral-to-formal and could easily appear in:

• science class
• health information
• product descriptions
• educational writing

That is mainly because of the word chất, which is more technical than many everyday nouns.

A casual conversation might use simpler wording depending on what exact substance is being discussed.

Yes. Có trong is a very common pattern meaning to be in, to be found in, or to be contained in something.

Examples:

• Vitamin C có trong cam. = Vitamin C is found in oranges.
• Đường có trong nước ngọt. = Sugar is in soda.
• Chất này có trong thực phẩm. = This substance is found in food.

This is a very useful pattern to learn.

You can put không before có:

• Chất này không có trong nước.

That means:

• This substance is not in water
• This substance is not found in water
• This substance is not present in water

So the pattern is:

[noun] + không có trong + [place/substance]

A simple yes/no question is:

• Chất này có trong nước không?

This means:

• Is this substance found in water?
• Is this substance present in water?

A very common Vietnamese pattern is:

[statement] + không?

So:

• có ... không? = is there / does it have / is it present?

A rough pronunciation guide is:

• Chất ≈ jut with a short, clipped ending
• này ≈ nye or nai depending on accent
• có ≈ gaw or koh with a rising tone
• trong ≈ chawng / trong
• nước ≈ nưək with a clipped ending

The tones are important:

• chất
• này
• có
• trong
• nước

If you are studying a specific accent, the exact pronunciation will differ a bit between northern and southern Vietnamese.