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2 years ago

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

Chemistry

2 answers:

UkoKoshka [18]2 years ago

8 0

Answer:

the substance dissolved

Explanation:

PolarNik [594]2 years ago

6 0

A. The substance dissolved. Just because a substance dissolved in a solvent doesn’t mean that a chemical action occurred. For example, if you put sugar in water as stir, it will dissolve, but the chemical make up of the sugar and the water don’t change. A chemical reaction can be indicated by a drastic change in color or temperature or if a substance precipitate.

Hope this helped :)

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Part A

Roman55 [17]

These are two questions and two answers

Question 1.

Answer:

7.33 × 10 ⁻³ c

Explanation:

1) Data:

a) m = 9.11 × 10⁻³¹ kg

b) λ = 3.31 × 10⁻¹⁰ m

c) c = 3.00 10⁸ m/s

d) s = ?

2) Formula:

The wavelength (λ), the speed (s), and the mass (m) of the particles are reltated by the Einstein-Planck's equation:

λ = h / (m.s)

h is Planck's constant: h= 6.626×10⁻³⁴J.s

3) Solution:

Solve for s:

s = h / (m.λ)

Substitute:

s = 6.626×10⁻³⁴J.s / ( 9.11 × 10⁻³¹ kg × 3.31 × 10⁻¹⁰ m) = 2.20 × 10 ⁶ m/s

To express the speed relative to the speed of light, divide by c = 3.00 10⁸ m/s

s = 2.20 × 10 ⁶ m/s / 3.00 10⁸ m/s = 7.33 × 10 ⁻³

Answer: s = 7.33 × 10 ⁻³ c

Question 2.

Answer:

2.06 × 10 ⁻³⁴ m.

Explanation:

1) Data:

a) m = 45.9 g (0.0459 kg)

b) s = 70.0 m/s

b) λ = ?

2) Formula:

Macroscopic matter follows the same Einstein-Planck's equation, but the wavelength is so small that cannot be detected:

λ = h / (m.s)

h is Planck's constant: h= 6.626×10⁻³⁴J.s

3) Solution:

λ = h / (m.s)

Substitute:

λ = 6.626×10⁻³⁴J.s / ( 0.0459 kg × 70.0 m/s) = 2.06 × 10 ⁻³⁴ m

As you see, that is tiny number and explains why the wave nature of the golf ball is undetectable.

Answer: 2.06 × 10 ⁻³⁴ m.

5 0

2 years ago

What is the theoretical yield of sodium oxide (Na₂O) in grams when 20.0g of calcium oxide (CaO) reacts with an excess amount of

ad-work [718]

Answer:

22.1g

Explanation:

We'll begin by writing the balanced equation for the reaction. This is given below:

CaO + 2NaCl —> Na2O + CaCl2

Next, we shall determine the mass of CaO that reacted and the mass of Na2O produced from the balanced equation.

This is illustrated below:

Molar mass of CaO = 40 + 16 = 56g/mol

Mass of CaO from the balanced equation = 1 x 56 = 56g

Molar mass of Na2O = (23x2) + 16 = 62g/mol

Mass of Na2O from the balanced equation = 1 x 62 = 62g

From the balanced equation above,

56g of CaO reacted to produce 62g of Na2O.

Finally, we can determine the theoretical yield of Na2O as follow:

From the balanced equation above,

56g of CaO reacted to produce 62g of Na2O.

Therefore, 20g of CaO will react to produce = (20 x 62)/56 = 22.1g of Na2O.

Therefore, the theoretical yield of Na2O is 22.1g

6 0

3 years ago

Read 2 more answers

I NEED HELP PLEASE, THANKS! :)

Free_Kalibri [48]

Answer:

Explanation:

Metallic character increases across a period to the left and downwards.

If you look at the periodic table, Cs is lower and more towards the left.

7 0

3 years ago

What is the experimental group? on edpuzzle

RideAnS [48]

An experimental group, also known as a treatment group, receives the treatment whose effect researchers wish to study, whereas a control group does not. They should be identical in all other ways

3 0

3 years ago

Read 2 more answers

If earth is 1.50 x 10^8km from the sun what is the distance in Mm?

Readme [11.4K]

The distance of the earth to the sun in Mm = 1.5 x 10⁵

<h3>Further explanation</h3>

Given

The distance of the earth to the sun : 1.50 x 10⁸ km

Required

The distance in Mm

Solution

In converting units we must pay attention to the conversion factor.

the conversion factor :

1 kilometer(km) = 10⁻³ megameter(Mm)

So the distance conversion :

1.5 x 10⁸ x 10⁻³ = 1.5 x 10⁵ Mm

8 0

2 years ago