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Maslowich
3 years ago
6

How do you think the human population has changed over time? What makes you say that?

Chemistry
1 answer:
kozerog [31]3 years ago
3 0

Answer:The world population increased from 1 billion in 1800 to 7.7 billion today. The world population growth rate declined from 2.2% per year 50 years ago to 1.05% per year. Other relevant research: World population growth – This article is focusing on the history of population growth up to the present.

Explanation:

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DA gas has a volume of 4.00 L at 0 degrees Celsius. What final temperature, in degrees Celsius, is needed to change the volume o
Sholpan [36]
D 50.O ML IS THE ANSWER

6 0
4 years ago
The average propane cylinder for a residential grill holds approximately 18 kg of propane. how much energy (in kj) is released b
never [62]
In order to answer this, we mus know the data for the heat of combustion of propane. This is an empirical data that you can search online. The heat of combustion is -2220 kJ/mol. The molar mass of propane of 44.1 g/mol. The solution is as follows:

ΔH = -2220 kJ/mol (1 mol/44.1 g)(1000g/1kg)(20 kg)
<em>ΔH = -1006802.721 kJ or -1 GJ</em>
8 0
3 years ago
Antacids are taken to counterbalance excess hydrochloric acid, HCl, in the stomach. Complete and balance the following neutraliz
abruzzese [7]

Answer:

1. CaCO3 + 2HCl —> CaCl2 + H2O + CO2

2. Mg(OH)2 + 2HCl —> MgCl2 + 2H2O

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7 0
3 years ago
Calculate the moles of oxygen gas which will react with 89.4 grams of iron.
Snowcat [4.5K]
<span>No of moles of Fe = Mass / Relative molar mass of Fe. So no of moles = 89.4/ 55.845 = 1.60. The. Chemical reaction is represented as follows. 4 Fe + 3 O2 which gives 2Fe2 O3 . This means that 4 atoms of Iron reacts with 3 atoms of Oxygen to produce Iron oxide. Hence 1.60*4 moles of Fe will need to react 1.6 * 3 moles of Oxygen to produce 2 moles of Iron oxide. Hence 4.8 moles of Oxygen will be required.</span>
3 0
4 years ago
Arrange the bonds between H, O, and F from most polar to least polar based on electronegativity.
Andrews [41]

Answer:

H-F> H-O> O-F

while H-H is nonpolar.

Explanation:

The bond is polar when electronegativity difference of both bonded atom is greater than 0.4.

Electronegativity values of O. F and H are

O = 3.4

H = 2.2

F = 3.98

For O-F

3.98 - 3.4 = 0.58

For H-F

3.98 - 2.2 = 1.78

For H-O

3.4 - 2.2 =  1.2

For H-H

2.2 -2.2 = 0

So H-H is nonpolar.

7 0
3 years ago
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