Este recipiente está vazio?

Because está vazio describes a temporary state: the container is empty right now.

In Portuguese, ser and estar both mean to be, but they are used differently:

• ser = for identity, essence, permanent characteristics
• estar = for condition, state, location, something that can change

So:

• O recipiente está vazio. = The container is empty right now.
• O recipiente é vazio. would sound unnatural in most situations, because emptiness is usually a condition, not an essential trait.

Este means this.

In traditional grammar:

• este = this, near the speaker
• esse = that, near the listener or a bit farther away
• aquele = that over there, farther from both

So Este recipiente literally means This container.

In everyday Brazilian Portuguese, many speakers use esse where older grammar would expect este, so you may also hear:

• Esse recipiente está vazio?

That is very common in speech. But este is still correct and often appears in writing, formal contexts, or careful speech.

Recipiente means container, vessel, or receptacle.

It is correct and clear, but it can sound a bit more formal or general than the words people often use in everyday speech. Depending on the object, Brazilians might more naturally say:

• copo = glass
• garrafa = bottle
• pote = jar/container
• caixa = box
• vasilha = container/dish
• embalagem = package/container

So Este recipiente está vazio? is grammatical and natural enough, but in real life people often choose a more specific noun.

Because vazio has to agree with the noun it describes.

Recipiente is a masculine noun in Portuguese, so the adjective must also be masculine:

• o recipiente vazio

If the noun were feminine, the adjective would change:

• a caixa vazia = the empty box
• a garrafa vazia = the empty bottle

Agreement also changes for plural:

• os recipientes vazios
• as caixas vazias

Yes. The normal word order here is:

• Este recipiente = subject
• está vazio = verb + adjective

That is the most straightforward way to say it.

You could also ask similar questions in other ways, for example:

• Este recipiente está vazio mesmo? = Is this container really empty?
• Está vazio este recipiente? = Is this container empty?
  This is possible, but less neutral and more marked.

For a basic yes/no question, the standard order is very common:

• Este recipiente está vazio?

No. Portuguese does not use an extra helping verb like do.

In English:

• Is this container empty?

In Portuguese, you usually use the same word order as a statement and rely on intonation or the question mark in writing:

• Statement: Este recipiente está vazio.
• Question: Este recipiente está vazio?

So Portuguese often forms yes/no questions simply by changing the tone of voice.

A rough pronunciation guide is:

• Este ≈ ES-chee or ES-tee depending on accent
• recipiente ≈ heh-see-pee-EN-chee in many Brazilian accents
• está ≈ es-TA
• vazio ≈ va-ZEE-oo

A few useful pronunciation notes:

• In many parts of Brazil, unstressed e at the end can sound like ee
• ti before a vowel often sounds like chee in many Brazilian accents
• The r at the start of recipiente usually sounds like an English h
• The stress is:
  • re-ci-pi-EN-te
  • es-TÁ
  • va-ZI-o

Usually, that would sound incomplete or unnatural in normal conversation.

Portuguese often allows omission of articles or pronouns in some contexts, but with a countable noun like recipiente, you normally want something before it:

• Este recipiente está vazio? = Is this container empty?
• O recipiente está vazio? = Is the container empty?
• Um recipiente está vazio? = Is a container empty?

Without a determiner, Recipiente está vazio? sounds more like a label, headline, or very telegraphic speech.

Yes, absolutely. In fact, in everyday Brazilian Portuguese, esse is often very common where learners might expect este.

So these are both possible:

• Este recipiente está vazio?
• Esse recipiente está vazio?

Very roughly:

• este can sound a bit more formal, careful, or written
• esse is extremely common in conversation

If you are speaking casually in Brazil, esse will often sound very natural.

Common answers include:

• Sim, está. = Yes, it is.
• Não, não está. = No, it isn’t.
• Sim, está vazio. = Yes, it’s empty.
• Não, está cheio. = No, it’s full.
• Está quase vazio. = It’s almost empty.
• Ainda tem um pouco. = There’s still a little left.

Portuguese often omits repeated information when it is obvious, just like English can.

No. Vazio can be used literally and figuratively.

Literal:

• O copo está vazio. = The glass is empty.
• A caixa está vazia. = The box is empty.

Figurative:

• A sala está vazia. = The room is empty.
• Ele se sente vazio. = He feels empty.
• O discurso foi vazio. = The speech was empty / lacking substance.

In your sentence, though, it is clearly the literal meaning: the container has nothing inside.