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3 years ago

Which of the following would indicate that a chemical change might be occurring

Chemistry

2 answers:

Murljashka [212]3 years ago

4 0

Explanation:

During a chemical change, a new kind of matter is formed. Examples are combustion, rusting of iron, precipitation and souring of milk.

Here are some of the properties of chemical change:

They are not easily reversible
It leads to the production of new kinds of matter.
It involves change in mass.
It requires a considerable amount of energy.

Learn more:

Chemical change brainly.com/question/9388643

#learnwithBrainly

RoseWind [281]3 years ago

3 0

Answer:

The options are missing in the question, so I am going to answer it in a general way.

There are several indicators of chemical reactions. They are:

Gas Bubbles Appear

Formation of a Precipitate

Color Change

Temperature Change

Production of Light

Volume Change

Change in Smell or Taste

Depending of what kind of reaction is occurring which indicator appear. For example in combustion reactions the temperature increase because they are highly exothermic; and in electrolysis of water, bubbles of molecular oxygen and molecular hydrogen are generated.

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1. a) Name two examples of good conductors?

Pachacha [2.7K]

A. good conductors - copper, aluminium

b. fair conductors - carbon,human body

c. insulator - paper, wood

7 0

3 years ago

78.9 + 890.43 - 21 = 9.5 x 10^2

maria [59]

948 or 9.48 x 10^2

There are two sets of rules for significant figures

• One set for addition and subtraction

• Another set for multiplication and division

You used the set for multiplication and division.

This problem involves addition and subtraction, and the rule is

The number of places after the decimal point in the answer must be <em>no greater than the number of decimal places in every term</em> in the sum.

Thus, we have

78.9

+890.43

-21.

= 948.33

The "21" term has the fewest digits after the decimal point (none), so the answer must have no digits after the decimal point.

To the correct answer is 948 = 9.48 x 10^2. It has three significant figures.

8 0

3 years ago

If the acceleration is 600 m/s/s and the mass is 300 kg, what force is acting on the object?

vampirchik [111]

Explanation:

Acceleration (a) = 600 m/s²

Mass (m) = 300 kg

Force (F) = ?

We know

F = m * a

= 300 * 600

=180000 Newton

The force acting on the object is 18000 Newton.

5 0

3 years ago

Read 2 more answers

Aclosed system contains an equimolar mixture of n-pentane and isopentane. Suppose the system is initially all liquid at 120°C an

garri49 [273]

Explanation:

The given data is as follows.

T = $120^{o}C$ = (120 + 273.15)K = 393.15 K,

As it is given that it is an equimolar mixture of n-pentane and isopentane.

So, $x_{1}$ = 0.5 and $x_{2}$ = 0.5

According to the Antoine data, vapor pressure of two components at 393.15 K is as follows.

$p^{sat}_{1}$ (393.15 K) = 9.2 bar

$p^{sat}_{1}$ (393.15 K) = 10.5 bar

Hence, we will calculate the partial pressure of each component as follows.

$p_{1} = x_{1} \times p^{sat}_{1}$

= $0.5 \times 9.2 bar$

= 4.6 bar

and, $p_{2} = x_{2} \times p^{sat}_{2}$

= $0.5 \times 10.5 bar$

= 5.25 bar

Therefore, the bubble pressure will be as follows.

P = $p_{1} + p_{2}$

= 4.6 bar + 5.25 bar

= 9.85 bar

Now, we will calculate the vapor composition as follows.

$y_{1} = \frac{p_{1}}{p}$

= $\frac{4.6}{9.85}$

= 0.467

and, $y_{2} = \frac{p_{2}}{p}$

= $\frac{5.25}{9.85}$

= 0.527

Calculate the dew point as follows.

$y_{1}$ = 0.5, $y_{2}$ = 0.5

$\frac{1}{P} = \sum \frac{y_{1}}{p^{sat}_{1}}$

$\frac{1}{P} = \frac{0.5}{9.2} + \frac{0.5}{10.2}$

$\frac{1}{P}$ = 0.101966 $bar^{-1}$

P = 9.807

Composition of the liquid phase is $x_{i}$ and its formula is as follows.

$x_{i} = \frac{y_{i} \times P}{p^{sat}_{1}}$

= $\frac{0.5 \times 9.807}{9.2}$

= 0.5329

$x_{z} = \frac{y_{i} \times P}{p^{sat}_{1}}$

= $\frac{0.5 \times 9.807}{10.5}$

= 0.467

4 0

3 years ago

A sample compound contains 5.723g Ag, 0.852g S and 1.695g O. Determine its empirical formula.

Lubov Fominskaja [6]

Answer:

$Ag_2SO_4$

Explanation:

Formula for the calculation of no. of Mol is as follows:

$mol=\frac{mass\ (g)}{molecular\ mass}$

Molecular mass of Ag = 107.87 g/mol

Amount of Ag = 5.723 g

$mol\ of\ Ag=\frac{5.723\ g}{107.87\ g/mol} =0.05305\ mol$

Molecular mass of S = 32 g/mol

Amount of S = 0.852 g

$mol\ of\ S=\frac{0.852\ g}{32\ g/mol} =0.02657\ mol$

Molecular mass of O = 16 g/mol

Amount of O = 1.695 g

$mol\ of\ O=\frac{1.695\ g}{16\ g/mol} =0.10594\ mol$

In order to get integer value, divide mol by smallest no.

Therefore, divide by 0.02657

$Ag, \frac{0.05305}{0.02657} \approx 2$

$S, \frac{0.02657}{0.02657} \approx 1$

$O, \frac{0.10594}{0.02657} \approx 4$

Therefore, empirical formula of the compound = $Ag_2SO_4$

7 0

3 years ago

Read 2 more answers