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abruzzese [7]
2 years ago
10

Which of the following sign does not indicate that a chemical change has happened .

Chemistry
1 answer:
Sever21 [200]2 years ago
4 0

Answer:

A.)

Explanation:

A change in state may seem like a chemical reaction, but it is actually a physical change. "A change in state" is basically saying that the appearance of whatever the item is, is taking a change physically. Whether this item was going through some examples of a physical change, which would be:

<em>melting (solid to liquid), evaporation (liquid to gas), condensation (gas to liquid), freezing (liquid to solid), deposition (gas to solid), and sublimation (solid to gas).</em>

A change in color, odor, taste, chemical compound, and temperature all represent a chemical reaction, because these are all things that are happening within the the item that is being given the product of a chemical change.

Think of it this way: <em>internal changes within the product: chemical. External changes within the product: physical.</em>

I hope this helps.

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Yeast converts glucose to ethanol and carbon dioxide during a process known as anaerobic fermentation. The chemical reaction is
Korolek [52]

Answer:

102g

Explanation:

To find the mass of ethanol formed, we first need to ensure that we have a balanced chemical equation. A balanced chemical equation is where the number of atoms of each element is the same on both sides of the equation (reactants and products). This is useful as only when a chemical equation is balanced, we can understand the relationship of the amount (moles) of reactant and products, or to put it simply, their relationship with one another.

In this case, the given equation is already balanced.

\tex{C_6H_{12}O_6} \longrightarrow 2 \ C_2H_6O + 2 \ CO_2

From the equation, the amount of ethanol produced is twice the amount of yeast present, or the same amount of carbon dioxide produced. Do note that amount refers to the number of moles here.

Mole= Mass ÷Mr

Mass= Mole ×Mr

<u>Method 1: using the </u><u>mass of glucose</u>

Mr of glucose

= 6(12) +12(1) +6(16)

= 180

Moles of glucose reacted

= 200 ÷180

= \frac{10}{9} mol

Amount of ethanol formed: moles of glucose reacted= 2: 1

Amount of ethanol

= 2(\frac{10}{9} )

= \frac{20}{9} mol

Mass of ethanol

= \frac{20}{9} \times[2(12)+6+16]

= \frac{20}{9}(46)

= 102 g (3 s.f.)

<u>Method 2: using </u><u>mass of carbon dioxide</u><u> produced</u>

Mole of carbon dioxide produced

= 97.7 ÷[12 +2(16)]

= 97.7 ÷44

= \frac{977}{440} mol

Moles of ethanol: moles of carbon dioxide= 1: 1

Moles of ethanol formed= \frac{977}{440} mol

Mass of ethanol formed

= \frac{977}{440} \times[2(12)+6+16]

= 102 g (3 s.f.)

Thus, 102 g of ethanol are formed.

Additional:

For a similar question on mass and mole ratio, do check out the following!

  • brainly.com/question/1685725
8 0
1 year ago
PLEASE HELP I got this wrong on an exam but got it wrong and i don’t know why!
lord [1]

Answer:

D.5,55cm+/-0,005cm

Explanation:

so this is the answer

5 0
3 years ago
Complete and balance the following acid-base reaction equation ______HNO3 + ______ Mg(OH)2 ------&gt;
jekas [21]

Answer

_2 HNO₃ + 1 Mg(OH)₂ → 1 Mg(NO₃)₂ + 2 H₂O

Explanation

Given:

______HNO3 + Mg(OH)2 ------>

Solution:

Note that the reaction between an acid and a base will give salt and water only.

Hence the complete reaction of the given equation is:

___HNO₃ + Mg(OH)₂ → Mg(NO₃)₂ + H₂O

To get the balanced equation for the acid-base reaction, 2 moles of HNO₃ will react with 1 mole of Mg(OH)₂ to produced 1 mole of Mg(NO₃)₂ and 2 moles of H₂O.

Therefore, the complete and balanced equation for the given acid-base reaction is:

_2 HNO₃ + 1 Mg(OH)₂ → 1 Mg(NO₃)₂ + 2 H₂O

5 0
1 year ago
Calculate number of moles of 4.4g of CO2 and 5.6L of NH3 . Pls help . Its urgent
kupik [55]
Moles of CO₂ = mass / molecular weight
Moles of CO₂ = 4.4 / (12 + 16 x 2)
Moles of CO₂ = 0.1 mol

Each mole of gas occupies 22.4 L at STP. Therefore,
Moles of NH₃ = 5.6 / 22.4
Moles of NH₃ = 0.25 mol
4 0
3 years ago
Is this an example of decomposition<br> 2CH4 + 402 → 2C02 + 4H2O
Molodets [167]

Answer:

Identify each equation as a composition reaction, a decomposition reaction, or neither.

Fe2O3 + 3 SO3 → Fe2(SO4)3

NaCl + AgNO3 → AgCl + NaNO3

(NH4)2Cr2O7 → Cr2O3 + 4 H2O + N2

Solution

In this equation, two substances combine to make a single substance. This is a composition reaction.

Two different substances react to make two new substances. This does not fit the definition of either a composition reaction or a decomposition reaction, so it is neither. In fact, you may recognize this as a double-replacement reaction.

A single substance reacts to make multiple substances. This is a decomposition reaction.

Test Yourself

Identify the equation as a composition reaction, a decomposition reaction, or neither.

C3H8 → C3H4 + 2 H2

Explanation:

I hope I help :)))

5 0
3 years ago
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