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3 years ago

Which radioisotope is used in dating geological formations?i-131u-238ca-37fr-220?

1 answer:

6 0

The radioisotope U-238 is primarily used in dating geologic formation. This method is used for dating sediments from either a marine or playa lake environment. Because this method is used for the period between 100,000 years and 1,200,000 years before the present, it aids in bridging the gap between the carbon-14 dating method and the potassium-argon dating method.

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At the boiling point, the vapor pressure of a liquid is equal to the _______.

Marat540 [252]

At the boiling point, the vapor pressure of a liquid is equal to the atmospheric pressure.

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3 years ago

One mole of an ideal gas<br><br> occupies a volume of 22.4<br><br> liters at

-Dominant- [34]

Answer : One mole of an ideal gas occupies a volume of 22.4 liters at STP.

Explanation :

As we know that 1 mole of substance occupies 22.4 liter volume of gas at STP conditions.

STP stands for standard temperature and pressure condition.

At STP, pressure is 1 atm and temperature is 273 K.

By using STP conditions, we get the volume of 22.47 liter.

Hnece, the one mole of an ideal gas occupies a volume of 22.4 liters at STP.

3 0

3 years ago

Gravitational Potential Energy is created when an object’s what changes

alisha [4.7K]

Answer:

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2 years ago

Draw the Lewis structure for NF3. What orbitals on N and F overlap to form bonds between these elements

jonny [76]

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2 years ago

Find the enthalpy of neutralization of HCl and NaOH. 137 cm3 of 2.6 mol dm-3 hydrochloric acid was neutralized by 137 cm3 of 2.6

liraira [26]

Answer : The correct option is, (D) 89.39 KJ/mole

Explanation :

First we have to calculate the moles of HCl and NaOH.

$\text{Moles of HCl}=\text{Concentration of HCl}\times \text{Volume of solution}=2.6mole/L\times 0.137L=0.3562mole$

$\text{Moles of NaOH}=\text{Concentration of NaOH}\times \text{Volume of solution}=2.6mole/L\times 0.137L=0.3562mole$

The balanced chemical reaction will be,

$HCl+NaOH\rightarrow NaCl+H_2O$

From the balanced reaction we conclude that,

As, 1 mole of HCl neutralizes by 1 mole of NaOH

So, 0.3562 mole of HCl neutralizes by 0.3562 mole of NaOH

Thus, the number of neutralized moles = 0.3562 mole

Now we have to calculate the mass of water.

As we know that the density of water is 1 g/ml. So, the mass of water will be:

The volume of water = $137ml+137ml=274ml$

$\text{Mass of water}=\text{Density of water}\times \text{Volume of water}=1g/ml\times 274ml=274g$

Now we have to calculate the heat absorbed during the reaction.

$q=m\times c\times (T_{final}-T_{initial})$

where,

q = heat absorbed = ?

$c$ = specific heat of water = $4.18J/g^oC$

m = mass of water = 274 g

$T_{final}$ = final temperature of water = 325.8 K

$T_{initial}$ = initial temperature of metal = 298 K

Now put all the given values in the above formula, we get:

$q=274g\times 4.18J/g^oC\times (325.8-298)K$

$q=31839.896J=31.84KJ$

Thus, the heat released during the neutralization = -31.84 KJ

Now we have to calculate the enthalpy of neutralization.

$\Delta H=\frac{q}{n}$

where,

$\Delta H$ = enthalpy of neutralization = ?

q = heat released = -31.84 KJ

n = number of moles used in neutralization = 0.3562 mole

$\Delta H=\frac{-31.84KJ}{0.3562mole}=-89.39KJ/mole$

The negative sign indicate the heat released during the reaction.

Therefore, the enthalpy of neutralization is, 89.39 KJ/mole

3 0

3 years ago