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2 years ago

Why do lunar and solar eclipse not happen every month

2 answers:

3 0

The moon's orbit is not perfectly aligned with the equator and the earth rotates on an axis around 20 degrees off, so the earth and the moon only line up with the sun once or twice a year.

mestny [16]2 years ago

3 0

Answer:

A lunar eclipse occurs when the Moon enters the Earth's shadow. A solar eclipse occurs when the Moon's shadow falls on the Earth. They do not happen every month because the Earth's orbit around the sun is not in the same plane as the Moon's orbit around the Earth.

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In the unbalanced equation given below, what is the element that is gaining electrons?

viktelen [127]

Hey there!:

HCl + MnO2 → MnCl2 + H2O + Cl2

* in HCl the oxidation state of Cl is -1 .

* on the product side the oxidation state is 0 .

* therefore Cl gains electrons .

* in MnO2 the oxidation state of Mn is +4

* in MnCl2 the oxidation state of Mn is +2

Therefore Mn loses electrons

Answer A

Hope That helps!

4 0

2 years ago

Read 2 more answers

Calculate the pH of a solution in which one normal adult dose of aspirin (640 mg ) is dissolved in 10 ounces of water. Express y

d1i1m1o1n [39]

The pH of the solution in which one normal adult dose aspirin is dissolved is : 2.7

Given data :

mass of aspirin = 640 mg = 0.640 g

volume of water = 10 ounces = 0.295735 L

molar mass of aspirin = 180.16 g/mol

moles of aspirin = mass / molar mass = 0.00355 mol

<h3>Determine the pH of the solution </h3>

First step : calculate the concentration of aspirin

= moles of Aspirin / volume of water

= 0.00355 / 0.295735

= 0.012 M

Given that pKa of Aspirin = 3.5

pKa = -logKa

therefore ; Ka = $10^{-3.5}$ = $3.162 * 10^{-4}$

From the Ice table

$3.162 * 10^{-4}$ = $\frac{x + H^+}{[aspirin]}$ = $\frac{x^{2} }{0.012-x}$

given that the value of Ka is small we will ignore -x

x² = $3.162 * 10^{-4} * 0.012$

x = $1.948 * 10^{-3}$

Therefore

[ H⁺ ] = $1.948 * 10^{-3}$

given that

pH = - Log [ H⁺ ]

= - ( -3 + log 1.948 )

= 2.71 ≈ 2.7

Hence we can conclude that The pH of the solution in which one normal adult dose aspirin is dissolved is : 2.7

Learn more about Aspirin : brainly.com/question/2070753

4 0

1 year ago

What is the empirical formula of propene CH3 CH2 CH2

kiruha [24]

Answer:

CH

Explanation:

Molecular formula of propene : C₃H₆

Take the HCF of carbon and hydrogen atoms :

3 = 3
6 = 2 x 3

Then, we can write the formula as :

3CH
This means there are 3 moles present

Empirical Formula :

Molecular Formula / No. of moles
C₃H₆ / 3
CH

The empirical formula of propene is CH

6 0

1 year ago

Please help!! i need the answer ASAP!

nirvana33 [79]

Answer:

23.34 %.

Explanation:

The percentage of water must be calculated as a mass percent.

We need to find the mass of water, and the total mass in one mole of the compound. For that we need to use the atomic masses of each element and take in consideration the number of atoms of each element in the formula unit.

Atomic masses of the elements:

Cd: 112.411 g/mol, N: 14.0067 g/mol, O: 15.999 g/mol, and H: 1.008 g/mol.

Mass of the formula unit:

Cd(NO₃)₂•4H₂O

mass of the formula unit = (At. mass of Cd) + 2(At. mass of N) + 10(At. mass of O) + 8(At. mass of H) = (112.411 g/mol) + 2(14.0067 g/mol) + 10(15.999 g/mol) + 8(1.008 g/mol) = 308.5 g/mol.

Mass of water in the formula unit:

mass of water = (4 × 2 × 1.008 g/mol) + (4 × 15.999 g/mol) = 72.0 g/mol.

So, the percent of water in the compound = [mass of water / mass of the formula unit] × 100 = [(72.0 g/mol)/(308.5 g/mol)] × 100 = 23.34 %

7 0

2 years ago

How many valence electrons does Carbonic Acid contain?

geniusboy [140]

4 carbon electrons. Hope this helps have a nice day

6 0

2 years ago