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3 years ago

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Which chemical equation represents a synthesis reaction?A.HCl + LiOH → LiCl + H2OB.2Na + MgCl2 → 2NaCl + Mg.H2CO3 → H2O + CO2D.C

+ O2 → CO2

1 answer:

Zina [86]3 years ago

6 0

Answer:

D

Explanation:

Just did it on A P E X

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Citric acid is one component of some soft drinks. Suppose that 8 L of solution are made from 0.24 g of citric acid, C6H8O7. What

stealth61 [152]

Answer:

The correct answer is 0.15 × 10⁻³ M.

Explanation:

C₆H₈O₇ is the molecular formula of citric acid. The mass of the one mole of the substance that comprise Avogadro's no of molecules is termed as the molar mass of the substance.

The molar mass of the citric acid (C₆H₈O₇) will be,

6 × atomic mass of carbon + 8 × atomic mass of hydrogen + 7 × atomic mass of oxygen = 6×12 + 8×1 + 7×16 = 192. Thus, the molar mass of citric acid is 192 g/mol.

The value of the solution given in the question is 8 L.

The mass of citric acid given is 0.24 g or 240 mg, which can also be written as 240/1000 g or 240 × 10⁻³ g.

The number of moles can be calculated by using the formula = mass / molar mass. Thus, by putting the values we get,

= 240 × 10⁻³ g / 192 g/mol

= 1.25 × 10⁻³ mol

The number of moles of the solute present in the 1 liter of the solution is termed as the molarity of the solution. The formula of molarity or M is,

= no of moles of solute / volume of solution in L

Now putting the values we get,

= 1.25 × 10⁻³ mol / 8 L

= 0.156 × 10⁻³ M

Hence, the molarity of citric acid in the given solution is 0.15 × 10⁻³ M

4 0

4 years ago

Question 5 options: The cell potential for an electrochemical cell with a Zn, Zn2 half-cell and an Al, Al3 half-cell is _____ V.

Mashcka [7]

Answer:

The voltage is $E_{cell} = 0.944 \ V$

Explanation:

Generally the half reaction for Zn, Zn2 half-cell is mathematically represented as

$Zn_{(s)}$ ⇔ $Zn^{2+}_{ (aq)} + 2e^-$ (reference study academy)

and the electric potential for this is a constant value

$E_{zn } = -0.7618 \ V$

Generally the half reaction for Al, Al3 half-cell is mathematically represented as

$Al^{3+} _{(aq)} + 3e^-$ ⇔ $Al_{(s)}$

and the electric potential for this is constant value

$E_{Al } = -1.662 \ V$

Therefore the cell potential for an electrochemical cell is mathematically represented as

$E_{cell} = E_{zn } - E_{Al }$

substituting values

$E_{cell} = -0.718 - (-1.662)$

$E_{cell} = 0.944 \ V$

4 0

3 years ago

A voltaic cell is constructed in which the anode is a Fe|Fe2 half cell and the cathode is a Cd|Cd2 half cell. The half-cell comp

Svetradugi [14.3K]

Answer: The Anode reaction is $Fe(s)\rightarrow Fe^{2+}(aq)+2e^-$

Explanation:

Oxidation-reduction reaction or redox reaction is defined as the reaction in which oxidation and reduction reactions occur simultaneously.

Oxidation reaction is defined as the reaction in which a substance looses its electrons.Oxidation occurs at anode.

Anode : $Fe(s)\rightarrow Fe^{2+}(aq)+2e^-$

Reduction reaction is defined as the reaction in which a substance gains electrons. Reduction occurs at cathode.

Cathode : $Cd^{2+}(aq)+2e^-\rightarrow Cd(s)$

3 0

3 years ago

commercial cold packs consist of solid NH4NO3 and water. In a coffee-cup calorimeter, 5.60g NH4NO3 is dissolved in 100g of water

fgiga [73]

Answer:

-1.37 kJ/mol

Explanation:

The expression for the calculation of the enthalpy of dissolution of [tex[NH_4NO_3[/tex] is shown below as:-

$\Delta H=m\times C\times \Delta T$

Where,

$\Delta H$ is the enthalpy of dissolution of [tex[NH_4NO_3[/tex]

m is the mass

C is the specific heat capacity

$\Delta T$ is the temperature change

Thus, given that:-

Mass of ammonium nitrate = 5.60 g

Specific heat = 4.18 J/g°C

$\Delta T=17.9-22.0\ ^0C=-4.1\ ^0C$

So,

$\Delta H=-1.25\times 4.18\times 3.9\ J=-95.9728\ J$

Negative sign signifies loss of heat.

Also, 1 J = 0.001 kJ

So,

$\Delta H=-0.096\ kJ$

Also,

Molar mass of [tex[NH_4NO_3[/tex] = 80.043 g/mol

The formula for the calculation of moles is shown below:

$moles = \frac{Mass\ taken}{Molar\ mass}$

Thus,

$Moles= \frac{5.60\ g}{80.043 \ g/mol}$

$Moles= 0.06996\ mol$

Thus, $\Delta H=-\frac{0.096}{0.06996}\ kJ/mol=-1.37\ kJ/mol$

6 0

3 years ago

Which of the following is the best definition of a physical property?

Harlamova29_29 [7]

Answer:

The answer is either A or C figure it out sorry

3 0

3 years ago