240 g of water (specific heat = 4.186 J/g°C, initial temperature = 20°C) is mixed with an
unknown mass of iron (specific heat = 0.444 J/gºC, initial temperature 500°C). When
equilibrium is reached, the system has a temperature of 42°С. Find the mass of iron.

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:

2.82 g

Explanation:

Step 1: Write the balanced precipitation reaction

3 Ba(NO₃)₂ (aq) + Al₂(SO₄)₃ (aq) ⇒ 3 BaSO₄(s) + 2 Al(NO₃)₃(aq)

Step 2: Calculate the reacting moles of Ba(NO₃)₂

45.0 mL (0.0450 L) of 0.548 M Ba(NO₃)₂ react.

0.0450 L × 0.548 mol/L = 0.0247 mol

Step 3: Calculate the moles of Al₂(SO₄)₃ that react with 0.0247 moles of Ba(NO₃)₂

The molar ratio of Ba(NO₃)₂ to Al₂(SO₄)₃ is 3:1. The reacting moles of Al₂(SO₄)₃ are 1/3 × 0.0247 mol = 8.23 × 10⁻³ mol

Step 4: Calculate the mass corresponding to 8.23 × 10⁻³ moles of Al₂(SO₄)₃

The molar mass of Al₂(SO₄)₃ is 342.2 g/mol.

8.23 × 10⁻³ mol × 342.2 g/mol = 2.82 g

Answer:

c

Explanation:

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:

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

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: 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].

Answer:

p o e t i c o

Explanation:

no lo entenderias

Answer:

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

Answer:ee

Explanation:

Answer:

See explanation.

Explanation:

Hello there!

3. In this case, according to the given question, it turns out possible for us to say that any chemical formula, for an ionic compound, has the cation (positive) on the left and the anion (negative) on the right; thus, since Mg is a metal, which tends to lose electrons and become positively charged whereas the Cl is a nonmetal, which tends to gain electrons and become negatively charged, we have the following:

[tex]Mg^{2+}Cl^-\\\\Mg^{2+}Cl^-_2\\\\MgCl_2[/tex]

4. In this case, since lithium is a metal, as well as magnesium, it is not possible for them to switch around their charges as they will not be bonded because they will be repelled rather than attracted because of their equal positive charges.

Regards!

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:

ako po kailangan ko po nga ayuda

Explanation:

thanks for the points ❤️

Explanation:

Chemistry is overall a very interesting subject and it really depends on what you personally consider enjoyable. I love chemistry and I think that grade 11 chemistry is very easy. It's mostly based on balancing chemical equation, molar mass calculations and more. But it's a great course to take based on my experience.

Answer:

I'm not really sure but I thinks its

A:veuns

Answer:

Taxonomy

Explanation:

[tex] \huge \mathrm{ \underline{Answer} ࿐}[/tex]

The correct option is B.

A Catalyst is a chemical which promotes or speed up a chemical reaction without undergoing any chemical reaction itself.

for example : potassium permanganate - Hydrogen peroxide will decompose into water and oxygen gas in the presence of KMnO4.

_____________________________

[tex]\mathrm{ \#TeeNForeveR}[/tex]

Answer:

Explanation:

Answer:

65.38 u

Explanation:

hope this helps you out!!!!!!!

They Mean D and not U H just took the test and its D i hope this help

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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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:

the original substances in any chemical reaction. products. the resulting substances in any....chromium(III) oxide, and water. (NH4)2Cr2O7(s) → N2(g) + Cr2O3(s) + 4H2O(g).

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:

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]

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.