Curium-242 undergoes alpha decay. In addition to the alpha particle, which

Determine the number of grams of carbon-14 remaining in this sample at 17,100 years.

earnstyle [38]

Answer: I need help

Explanation:

8 0

3 years ago

For a process Arightwards harpoon over leftwards harpoonB, at 25 °C there is 10% of A at equilibrium while at 75 °C, there is 80

Lostsunrise [7]

This question is describing the following chemical reaction at equilibrium:

$A\rightleftharpoons B$

And provides the relative amounts of both A and B at 25 °C and 75 °C, this means the equilibrium expressions and equilibrium constants can be written as:

$K_1=\frac{90\%}{10\%}=9\\\\K_2=\frac{20\%}{80\%} =0.25$

Thus, by recalling the Van't Hoff's equation, we can write:

$ln(K_2/K_1)=-\frac{\Delta H}{R}(\frac{1}{T_2} -\frac{1}{T_1} )$

Hence, we solve for the enthalpy change as follows:

$\Delta H=\frac{-R*ln(K_2/K_1)}{(\frac{1}{T_2} -\frac{1}{T_1} ) }$

Finally, we plug in the numbers to obtain:

$\Delta H=\frac{-8.314\frac{J}{mol*K} *ln(0.25/9)}{[\frac{1}{(75+273.15)K} -\frac{1}{(25+273.15)K} ] } \\\\\\\Delta H=4,785.1\frac{J}{mol}$

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5 0

2 years ago

7. Suppose 1.01 g of iron (III) chloride is placed in a 10.00-mL volumetric flask with a bit of water in it. The flask is shaken

Nana76 [90]

Answer: The molarity of Iron (III) chloride is 0.622 M.

Explanation:

Molarity is defined as the number of moles present in one liter of solution. The equation used to calculate molarity of the solution is:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$

Or,

$\text{Molarity of the solution}=\frac{\text{Mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Volume of solution (in mL)}}$

We are given:

Mass of iron (III) chloride = 1.01 g

Molar mass of iron (III) chloride = 162.2 g/mol

Volume of the solution = 10 mL

Putting values in above equation, we get:

$\text{Molarity of Iron (III) chloride}=\frac{1.01g\times 1000}{162.2g/mol\times 10mL}\\\\\text{Molarity of Iron (III) chloride}=0.622M$

Hence, the molarity of Iron (III) chloride is 0.622 M.

3 0

2 years ago

HelpppA swamp is a wetland habitat that contains areas that are temporarily or permanently flooded. The Okefenokee Swamp is loca

FrozenT [24]

Wading birds live successfully in the swamp because : B) Their long legs allow them to wade in the waters without getting wet.

Explanation:

Wading birds are common habitat in swamp and muddy areas.

Some wadding birds are crane, egret, heron, sandpipers and ibis

Some characteristics of wading birds are:

long, thin legs. Also, they have large toes
long bills and long strong necks

Long legs of wadding birds allow them to walk easily in wetland without getting their feathers wet.

They live in water or near water, so their food are mainly aquatic insects, small amphibians and fishes.

Wading birds are also called shorebirds.

8 0

3 years ago

Which of the following statements is TRUE? Which of the following statements is TRUE? Electrons placed in antibonding orbitals s

marusya05 [52]

Answer:

When two atomic orbitals come together to form two molecular orbitals, one molecular orbital will be lower in energy than the two separate atomic orbitals and one molecular orbital will be higher in energy than the separate atomic orbitals.

Explanation:

Which of the following statements is TRUE?

Electrons placed in antibonding orbitals stabilize the ion/molecule. FALSE. Electrons in the antibonding orbitals destabilize the ion/molecule.

The total number of molecular orbitals formed doesn't always equal the number of atomic orbitals in the set. FALSE. The total number of molecular orbitals is always equal to the number of atomic orbitals in the set.

When two atomic orbitals come together to form two molecular orbitals, one molecular orbital will be lower in energy than the two separate atomic orbitals and one molecular orbital will be higher in energy than the separate atomic orbitals. TRUE. The orbital with lower energy will be the bonding orbital and the one with higher energy will be the antibonding orbital.

A bond order of 0 represents a stable chemical bond. FALSE. A chemical bond is stable if the bond order is higher than zero.

5 0

3 years ago