is chemistry hard in grade 11
explain to me everything plsss thanks ​

Answer:

A

Explanation:

got from another website

The simulation which is least suitable to scientists for solving a problem is when performing an experiment that would be too costly or dangerous to conduct in the real world.

Scientific approach is an empirical method of acquiring knowledge and result. This method involved the careful observation of the problem, applying skepticism about the problem and giving cognitive assumptions also.

If a scientist wants to investigate several problems, then they will perform a large no. of trials at regular intervals to get the required result. But if performing of any experiment is dangerous to conduct in the real world then scientists will ignore to solve that problem.

Hence, option (C) is correct.

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Answer:

190 L

Explanation:

Given that:

Number of moles = mass/molar mass

number of moles = 5.64

molar mass of aluminum chloride = 133.34 g/mol

∴

The balanced equation is:

2 Al + 3 Cl2 --> 2AlCl3.

From above reaction:

5.64 mole of  AlCl3 reacts with 3 mole Cl2  to give 2 mole AlCl3

i.e

[tex](5.64 \ mole \ AlCl3) \times (3 \ mole \ Cl2 \ / \ 2 \ mole \ AlCl3)[/tex]

= 8.46 mole Cl2 gas.

At Standard temperature and pressure:

= (22.4 L/1 mole gas) * (8.46 mole Cl2)

= 190 L chlorine gas

Answer: The concentration of [tex]NO_{2}[/tex] in the given equilibrium mixture is 0.0545 M.

Explanation:

The ratio of concentration of products and reactants raised to the power of their coefficients is called equilibrium constant. The symbol used to denote equilibrium constant is [tex]K_{eq}[/tex].

As the given reaction equation is as follows.

[tex]2NO_{2}(g) \rightleftharpoons N_{2}O_{4}(g)[/tex]

The expression for equilibrium constant of this reaction is as follows.

[tex]K_{eq} = \frac{[N_{2}O_{4}]}{[NO_{2}]^{2}}[/tex]

Now, substitute the given values into above formula as follows.

[tex]K_{eq} = \frac{[N_{2}O_{4}]}{[NO_{2}]^{2}}\\67.3 = \frac{(0.2)}{[NO_{2}]^{2}}\\So, [NO] = \sqrt{\frac{0.2}{67.3}}\\= 0.0545 M[/tex]

Thus, we can conclude that the concentration of [tex]NO_{2}[/tex] in the given equilibrium mixture is 0.0545 M.

Answer:

six cookies?(1 cal _4.184 j; ALSO: 1 Calorie -1 kilocalorie)

Answer:

4.78 mol O2

Explanation:

Grams --> moles

Grams/molar mass = moles

153 g O2 / 32 g/mol O2 = 4.78125 (significant figures so round it up; the grams has 3 significant figures, so round it up) 4.78 mol O2

Answer: The standard state refers to 1 atm and [tex]25^{o}C[/tex].

Explanation:

It is known that a chemical/substance can either be present in a solid, liquid or gaseous state.

So, when the phase of a substance like solid, liquid or gas is present at 1 atmosphere pressure and at a temperature of [tex]25^{o}C[/tex] then it known as standard state of substance.

Thus, we can conclude that standard state refers to 1 atm and [tex]25^{o}C[/tex].

Answer:ee

Explanation:

Answer:

I'm not really sure but I thinks its

A:veuns

Answer:

Taxonomy

Explanation:

When leaves fall from a tree and decompose on the soil it benefits the ecosystem as nutrients are released into the soil.

Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.

Energy enters the system through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.

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A dry cell is one type of electric battery which is generally used for the home and portable electronic devices. A battery is a device which consists of one or more electrochemical cells. The site of oxidation occurs in solid zinc layer. The correct option is A.

A dry cell is defined as an electrochemical cell which consists of low moisture immobilized electrolytes in the form of a paste which restricts it from flowing. It is developed by the German scientist Carl Gassner which converts chemical energy into electrical energy.

A dry cell consists of a metal container in which a low moisture electrolyte paste covers the graphite rod or a metal electrode. Generally, the metal container will be zinc whose base perform as the negative electrode (anode).

For a dry cell battery to operate, oxidation  will occur from the zinc anode and reduction will take place in the cathode.

Thus the correct option is A.

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Answer:

Ag(I)C2H3O2 ....................

Silver only has a single valence value (+1) so you really don't need to put the (I) in the chemical formula.

Answer:

four

is the answer

Answer:

hot water is thinner than cold water.

Explanation:

The rate of diffusion of a substance has a lot to do with the temperature of a body.

Let us take water for instance, cold water has a greater density than hot water. As a result of this, the molecules in cold water are slower when in motion and more sluggish.

On the other hand, the molecules of hot water are quite faster since hot water has a lower density(thinner than cold water).

Thus, an  increase in temperature will cause an increase in diffusion rate because hot water is thinner than cold water.

Answer:

p o e t i c o

Explanation:

no lo entenderias

Answer:

The right answer is "[tex][Na^+]=5.57 \ ppm[/tex]".

Explanation:

The given values are:

[tex]\frac{A_s}{A_{coffee}} =\frac{0.840}{1.000}[/tex]

According to the question,

The concentration of standard will be:

=  [tex]\frac{7.80}{50.00}\times 4.80[/tex]

=  [tex]0.156\times 4.80[/tex]

=  [tex]0.748 \ ppm[/tex]

Coffee after dilution,

⇒  [tex]\frac{A_{coffee}}{C_{coffee}} =F\times \frac{A_s}{C_s}[/tex]

or,

⇒  [tex]C_{coffee}=\frac{A_{coffee}}{A_s}\times \frac{C_s}{F}[/tex]

On substituting the values, we get

⇒               [tex]=\frac{1.000}{0.840}\times \frac{0.748}{1.68}[/tex]

⇒               [tex]=1.191\times 1.3104[/tex]

⇒               [tex]=1.561 \ ppm[/tex]

hence,

In unknown sample, the concentration of coffee will be:

=  [tex]1.561\times \frac{50}{14}[/tex]

=  [tex]\frac{78.05}{14}[/tex]

=  [tex]5.57 \ ppm[/tex]

Answer:

500J (joules)

Explanation:

since heat is is the product of mass, change in temperature, and specific heat, the solution can be found from the equation q = mcΔt, heat is 50 * .5 * 20 = 500J

Plants!

No doubt the answer is plants they are one maintaining the temperature, responsible for rains too...

Answer:

Explanation:

Answer:

I'd there and pictures?? can put the list

Answer: There are [tex]145 \times 10^{23}[/tex] atoms in 24 moles of Fe.

Explanation:

According to the mole concept, 1 mole of a substance contains [tex]6.022 \times 10^{23}[/tex] atoms.

Therefore, atoms present in 24 moles of Fe are calculated as follows.

[tex]24 mol \times 6.022 \times 10^{23} atoms/mol\\= 144.52 \times 10^{23} atoms\\or, 145 \times 10^{23} atoms[/tex]

Thus, we can conclude that there are [tex]145 \times 10^{23}[/tex] atoms in 24 moles of Fe.

Answer:

The appropriate solution is:

(a) n ≈ 900

(b) n ≈ 1165

Explanation:

According to the question,

(a)

The final number of molecules throughout water will be:

= [tex](\frac{1000}{1000}\times 4\times 10 )^n[/tex]

where, n = number of extractions

Now,

The initial number of molecules will be:

= [tex]1.06\times 10^{-4}\times 6.023\times 10^{23}[/tex]

= [tex]6.387\times 10^{19}[/tex]

Final number of molecule,

⇒ [tex]1.566\times 10^{-16}=(\frac{1000}{1040} )^n[/tex]

                       [tex]n \approx 900[/tex]

(b)

Final molecules of X = left (0.01%)

hence,

⇒ [tex]initial = 6.384\times 10^{19}[/tex]

   [tex]\frac{1}{6.384\times 10^{19}} =(\frac{1000}{1040} )^2[/tex]

                 [tex]n \approx 1165[/tex]

Answer:

moles MgCl₂ = 5.97 moles

Explanation:

First, let0s write the overall reaction that is taking place here:

Mg(OH)₂ + HCl ----------> MgCl₂ + H₂O

Now, we need to balance this reaction:

Mg(OH)₂ + 2HCl ----------> MgCl₂ + 2H₂O

Now, the exercise already stated that the HCl is in excess, so we can assume the magnesium hydroxide is the limiting reactant. If this is true, then, to get the moles of MgCl₂ produced, all we need to do is calculate the moles of Mg(OH)₂ that reacted, using the following expression:

moles = mass / MM

The atomic weights for Mg, O and H are:

Mg: 24.305 g/mol;  H: 1 g/mol;  O = 15.999 g/mol

Let's determine the molar mass of Mg(OH)₂:

MM = 24.305 + (2 * 15.999) + (2 * 1) = 58.303 g/mol

Now, let's determine the moles:

moles = 348 g / 58.303 g/mol = 5.97 moles of Mg(OH)₂

As we can see in the overall reaction, there is a mole ration between Mg(OH)₂ and MgCl₂ of 1:1, that's why we can conclude that the moles of Mg(OH)₂ would be the same moles of MgCl₂:

Hope this helps

Answer:

- log{H+ }= - log {5}= -0.6990

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Definition:-

The organ of government that primarily looks after the function of implementation and administration is called the executive.

Function:-

Executive is the branch of government responsible for the implementation of laws and policies adopted by the legislature.

Answer: 61 μg of aluminum phosphate in grams is equal to [tex]61 \times 10^{-6} g[/tex].

Explanation:

According to standard conversion of units, 1 microgram [tex](\mu g)[/tex] is equal to [tex]1 \times 10^{-6}[/tex] g.

Therefore, [tex]61 \mu g[/tex] is converted into grams as follows.

[tex]1 \mu g = 10^{-6} g\\61 \mu g = 61 \mu g \times \frac{10^{-6}}{1 g}\\= 61 \times 10^{-6} g[/tex]

Thus, we can conclude that 61 μg of aluminum phosphate in grams is equal to [tex]61 \times 10^{-6} g[/tex].