What does the pH of a solution indicate

Describe the law of conservation of mass and how it applies to chemical reactions.

Lera25 [3.4K]

Answer:

the law of conservation of mass is whatever goes into a reaction comes out nothing is lost or gianed.

Explanation:

7 0

3 years ago

What is latice energy

velikii [3]

The energy required to separate a mole of an ionic solid into gaseous ions

3 0

3 years ago

A liquid-fueled rocket engine has two liquids, usually called the fuel and the oxidizer. Which two liquids are most commonly use

hammer [34]

Answer:

A liquid-fueled rocket has two liquids (liquids are good because of the density, they need less space than a gas to be stored), such that these liquids are called the fuel and the oxidizer.

These liquids are injected into a system that leads to a combustion chamber, where the liquids are mixed (we need to mix the fuel with the oxidizer to enable the combustion of the fuel) and burned to produce thrust.

Some common examples of oxidizers are liquid oxygen, which may be combined with fuels like liquid hydrogen, liquid methane, kerosene and hydrazine.

Other oxidizers are liquid fluorine (which also can be combined with the fuels liquid hydrogen and hydrazine), nitrogen tetroxide (which can be combined whit kerosene, hydrazine and other fuels) and FLOX-70, which can only be combined with kerosene.

The "most commonly used" may depend on the country and the type of liquid propellant ( petroleum, cryogens, and hypergols)

Such that the most common oxidizer may be liquid oxygen, and the most common fuel the kerosene.

8 0

3 years ago

2 points

erica [24]

9 grams of hydrogen gas (H2) will SC Johnson need to react in order to make 1 bottle of Windex.

Explanation:

Balance equation for the formation of ammonia from H2 gas.

N2 + 3H2 ⇒ 2 $NH_{3}$

Given

mass of ammonia in 1 bottle of windex = 51 gram

atomic mass of ammonia 17.01 gram/mole

number of moles = $\frac{mass}{atomic mass of 1 mole}$

number of moles = $\frac{51}{17.01}$

= 3 moles of ammonia is formed.

in 1 bottle of windex there are 3 moles of ammonia 0r 51 grams of ammonia.

From the equation it can be found that:

3 moles of hydrogen reacted to form 2 moles of ammonia

so, x moles of hydrogen will react to form 3 moles of ammonia.

$\frac{2}{3}$ = $\frac{3}{x}$

x = 4.5 moles of hydrogen will be required.

to convert moles into gram formula used:

mass = atomic mass x number of moles (atomic mass of H2 is 2grams/mole)

= 2 x 4.5

= 9 grams of hydrogen.

7 0

3 years ago

The natural abundances of elements in the human body, expressed as percent by mass, are: oxygen (O),65 percent; carbon (C), 18 p

almond37 [142]

Answer:

The mass in grams of each element in the body of 62 Kg are

Oxygen 40300 g

Carbon 11160 g

Hydrogen 6200 g

Nitrogen 1860 g

Calcium 992 g

Phosphorus 744 g

Other elements 744 g

It is possible to check it adding all the components, the total is 62000 g.

Explanation:

Firstly, we have a total mass of 62 Kg and the composition as a percentage of each component.

Percentage ( %)

Oxygen 65.0

Carbon 18.0

Hydrogen 10.0

Nitrogen 3.0

Calcium 1.6

Phosphorus 1.2

Other elements 1.2

Taking the definition of a percentage as part of hundred total, each percentage can be expressed as a decimal number. We should divide the percentage with 100 of total. For example: Oxygen 65%, it means 65/100 = 0.65. So, Oxygen is 0.65 in decimal numbers. We do the same for each component.

Percentage ( %) Decimal number

Oxygen 65.0 65/100 = 0.65

Carbon 18.0 18/100 = 0.18

Hydrogen 10.0 10/100 = 0.10

Nitrogen 3.0 3/100 = 0.03

Calcium 1.6 1.6/100 = 0.016

Phosphorus 1.2 1.2/100 = 0.012

Other elements 1.2 1.2/100 = 0.012

Finally. We can multiply decimal number of each component taking the total. 1 Kg is equivalent to 1000 g.

So, 62 Kg = 62 * 1000 g = 62000 g

After that we get the mass in grams of each element, by multiplying 62000 g and the decimal number of each component as follows:

Percentage ( %) Decimal number Mass in grams (g)

Oxygen 65.0 65/100 = 0.65 0.65*62000=40300

Carbon 18.0 18/100 = 0.18 0.18*62000= 11160

Hydrogen 10.0 10/100 = 0.10 0.10*62000= 6200

Nitrogen 3.0 3/100 = 0.03 0.03*62000= 1860

Calcium 1.6 1.6/100 = 0.016 0.016*62000= 992

Phosphorus 1.2 1.2/100 = 0.012 0.012*62000=744

Other elements 1.2 1.2/100 = 0.012 0.012*62000=744

5 0

3 years ago