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3 years ago

Which of the following is not an indication of a chemical reaction?

Chemistry

2 answers:

lakkis [162]3 years ago

8 0

A substance freezes.

Y_Kistochka [10]3 years ago

3 0

Answer:

A substance freezes

Explanation:

Two substances bursting into flames on contact can be seen as a combustion reaction, and this usually happens with very volatile substances, and is a chemical reaction that changes the substance on the atomic level.

A substance freezing simply demonstrates a phase change, and does not alter the molecule on any level, apart from the arrangement of the atoms.

Bubbles forming when two substances are combined is the indication that a gas has been formed as a product. The only way a gas can be formed is by a chemical change, usually oxygen or hydrogen is given off.

A solid forming is usually named a precipitation reaction, and the solid is called a precipitate, and this is a chemical reaction that forms an insoluble substance.

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How many grams of carbon (C) would be present in carbon monoxide (CO) that contains 2.666 grams of oxygen (O)? For example if th

oee [108]

Given :

Mass of oxygen containing carbon monoxide (CO) is 2.666 gram .

To Find :

How many grams of carbon (C) would be present in carbon monoxide (CO) that contains 2.666 grams of oxygen (O) .

Solution :

By law of constant composition , a given chemical compound always contains its component elements in fixed ratio (by mass) and does not depend on its source and method of preparation.

So , volume of solution does not matter .

Moles of oxygen , $n=\dfrac{2.666}{16}=0.167\ mole$ .

Now , molecule of CO contains 1 mole of C .

So , moles of C is also 0.167 mole .

Mass of carbon , $m=12\times 0.167=2\ g$ .

Therefore , mass of carbon is 2 grams .

Hence , this is the required solution .

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3 years ago

A car with a mass of 3700kg. accelerates at a rate of 8.0 m/s^2 in the backward direction. What is the net force acting on the c

Digiron [165]

Answer:

300

Explanation:

bcuz why not

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3 years ago

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Vanyuwa [196]

The most appropriate answer is C !!

4 0

3 years ago

The volume of a gas is the same as its _____.

AleksandrR [38]

The volume of a gas is the same as its CONTAINER.

Gases generally has no shape and no definite volume. When a gas is placed in a container, the gas usually takes the shape and the volume of the container, that is, the gas fills up all the available spaces in the container. Thus, the volume of a gas will always be the same as its container. This is in contrast with solids, which have definite shape and volume and liquids, which have definite volume but no fixed shape.

8 0

3 years ago

Read 2 more answers

Student perfotms a Benedict's test on an unknown substance. He adds reagent(the chemical required to make a color change), and n

elixir [45]

Answer:

Reducing sugars are absent

Explanation:

Benedict's solution is an substance used in testing sugars. It is mixture of sodium carbonate, sodium citrate and copper(II) sulfate pentahydrate. It can be used instead of Fehling's solution in testing for the presence of reducing sugars.

Reducing sugars contain the -CHO group. If there is no colour change after the addition of Benedict's solution, then we can conclude that reducing sugars are absent.

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3 years ago