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4 years ago

Most electricity is generated by

1 answer:

4 0

Electricity is most often generated at a power station by electromechanical generators, primarily driven by heat engines fueled by combustion or nuclear fission but also by other means such as the kinetic energy of flowing water and wind. Other energy sources include solar photovoltaics and geothermal power. You Mathematical Anser Would Be A

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In mutualism _____.

yawa3891 [41]

Answer:

3'' one is correct answer

Explanation:

in mutualism, organisms of different species benefit from cooperation

8 0

3 years ago

What mass of water should be added to 22.0 g of KCl to make a 5.50 % by mass solution?

Naddik [55]

383.5 grams is the mass of water should be added to 22.0 g of KCl to make a 5.50 % by mass solution.

Explanation:

Given that:

Solution to be prepared is 5.5 %

mass of KCl is 22 gram

mass of water required =?

5.5 % solution means that

5.5 grams in 100 ml or gram of water to make solution.

let the water required is 5.5 + x, so the equation will be

5.5 = $\frac{22}{22+x}$ x 100

121+ 5.5x = 2200

5.5 x = 2200-121

x = $\frac{2079}{5.5}$

x = 378 grams

The mass of water added to KCl to make it 5.5% percent solution is

5.5 +378

= 383.5 grams.

to make the solution of 5.5 percent of KCl weighing 22 grams.

8 0

3 years ago

Calculate the pH of: (a) 0.1M HCl; (b) 0.1M NaOH; (c) 3 X 10% M HNO3; (d) 5 X 10-10 M HCIO.; and (e) 2 x 10-8 M KOH.

Shtirlitz [24]

Answer:

(a) $pH = -Log (0.1M) = 1$

(b) $pH = -Log (10^{-13}M) = 13$

(d) $pH = -Log (4.93x10^{-10}M) = 9.3$

(e) $pH = -Log (5^{-7}M) = 6.3$

Explanation:

To calculate de pH of an acid solution the formula is:

$pH = -Log ([H^{+}]) = 1$

were [H^{+}] is the concentration of protons of the solution. Therefore it is necessary to know the concentration of the protons for every solution in order to solve the problem.

(a) and (c) are strong acids so they dissociate completely in aqueous solution. Thus, the concentration of the acid is the same as the protons.

(b) and (e) are strong bases so they dissociate completely in aqueous solution too. Thus, the concentration of the base is the same as the oxydriles. But in this case it is necessary to consider the water autoionization to calculate the protons concentration:

$K_{w} =[H^{+} ][OH^{-}]=10^{-14}$

clearing the $[H^{+} ]$

$[H^{+} ]=\frac{10^{-14}}{[OH^{-}]}$

(d) is a weak base so it is necessary to solve the equilibrium first, knowing $Ka=3.24x10^{-8}$

The reaction is $HClO$ → $H^{+} + CO^{-}$ so the equilibrium is

$Ka=3.24x10^{-8}=\frac{x^{2}}{5x10^{-8}-x}$

clearing the <em>x</em>

${x^{2}={1.62x10^{-17}-3.24x10^{-8}x}$

$x=[H^{+}]=4.93x10^{-10}$

6 0

4 years ago

Where else do you see Force & Motion in real-world experiences?

Paladinen [302]

Answer:

a boy pulling a toy train, the boy is

interacting with an object while applying a force to it,

another example of contact forces is friction.

Explanation:

A contact force is when two interacting

objects

(btw love your pfp)

4 0

3 years ago

Read 2 more answers

Theobromine (greek theobroma, meaning "food of the gods") is a common constituent in coca. fill in all the lone pairs on each he

Ganezh [65]

The lone pair of electrons in Theobromine are shown in RED color in attached figure.

Details:

In chemistry there are two types of electrons.

i) Bonding Pair Electrons:

These are those electrons which are being shared and are involved in making bonds. They are also called as sharing electrons. In given structure all the solid bonds either single or double are made up of bonding pair electrons.

ii) Lone Pair / Non-Bonding Pair Electrons:

Those electrons which doesn't take part in bonding and are not shared between atoms. In given structure the lone pair of electrons are found only on nitrogen atoms (single lone pair) and oxygen atoms (two lone pair of electrons) respectively.

Hybridization of Nitrogen Atoms;

N₁ = Sp²

N₂ = Sp³

N₃ = Sp³

N₄ = Sp³

Hybridization of Oxygen Atoms;

O₁ = Sp²

O₂ = Sp²

8 0

3 years ago