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2 years ago

According to astronomers , the age of the universe is estimated to be

1 answer:

3 0

The age of the universe is approximately 13.8 billion years old. The universe is constantly expanding. A universe with a low density of matter is older than a matter – dmominated one. To determine the density and composition of the universe, scientists rely on missions such as NASA’s Wilkinson Microwave Anisotropy Probe spacecraft. They measure the thermal radiation left from Big Bang.

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Construct the inequality for the following cases.

Rudik [331]

Answer:

x + y < 50

Explanation:

8 0

2 years ago

How can a redox reaction be used as a source of electrical energy?

stepladder [879]

A redox reaction be used as a source of electrical energy only when two half-reactions are physically separated. The electrons that are released at the anode flow through the wire, producing an electric current. Galvanic cells therefore transform chemical energy into electrical energy that can then be used to do work.

8 0

3 years ago

Read 2 more answers

When heated, magnesium combines readily with excess oxygen in the air to produce magnesium oxide, as shown in the following unba

aev [14]

Answer: The given chemical reaction can be classified as synthesis and exothermic.

Explanation:

A synthesis reaction is defined as the reaction where two small chemical species combine in their elemental state to form a single large chemical species.

Exothermic reactions are defined as the reactions in which heat is released by the reaction. The heat is written on the product side of the reaction.

For the given chemical reaction:

$Mg(s)+O_2(g)\rightarrow MgO(s)+\text{heat}$

The above chemical reaction is a type of synthesis and exothermic as two substances in their elemental state are combining. Also, heat is getting released in the reaction.

Hence, the given chemical reaction can be classified as synthesis and exothermic.

4 0

2 years ago

Menthol, which is present in mentholated cough drops, is an organic compound

Pie

Answer:

The empirical formula is C10H20O

Explanation:

Step 1: Data given

Mass of the sample = 0.2010 grams

Mass of CO2 = 0.5658 grams

Molar mass CO2 = 44.01 g/mol

Mass of H2O = 0.2318 grams

Molar mass H2O = 18.02 g/mol

Atomic mass C = 12.01 g/mol

Atomic mass O = 16.0 g/mol

Atomic mass H = 1.01 g/mol

Step 2: calculate moles CO2

Moles CO2 = 0.5658 gram / 44.01 g/mol

Moles CO2 = 0.01286 moles

Step 3: Calculate moles C

For 1 mol CO2 we have 1 mol C

For 0.01286 moles CO2 we have 0.01286 moles C

Step 4: Calculate mass C

MAss C = 0.01286 moles * 12.01 g/mol

Mass C =0.1544 grams

Step 5: Calculate moles H2O

Moles H2O =0.2318 grams / 18.02 g/mol

Moles H2O = 0.01286 moles

Step 6: Calculate moles H

For 1 mol H2O we have 2 moles H

For 0.01286 moles H2O we have 2*0.01286 = 0.02572 moles H

Step 7: Calculate mass H

Mass H = 0.02572 moles * 1.01 g/mol

Mass H = 0.0260 grams

Step8: Calculate mass O

Mass O = 0.2010 - 0.1544 - 0.0260

Mass O = 0.0206 grams

Step 9: Calculate moles O

Moles O = 0.0206 grams / 16.0 g/mol

Moles O = 0.00129 moles

Step 10: Calculate the mol ratio

We divide by the smallest amount of moles

C: 0.01286 moles / 0.00129 moles = 10

H: 0.02572 moles / 0.00129 moles = 20

O: 0.00129 moles / 0.00129 moles = 1

The empirical formula is C10H20O

4 0

3 years ago

Read 2 more answers

explain why particles of colloidal solution donot settle down when left undisturbed , while in the case of suspensions they do .

Leni [432]

Answer:

the partial of colloidal are smaller and they are not heavy whereas the partial of suspension are larger but they are heavy and less movement thus they settle down due to gravity

7 0

2 years ago