Same force on two object of different masses

Lithium, is used in dry cells and storage batteries and in high temperature lubricants, it has two naturally occurring isotopes,

erastovalidia [21]

Answer: The average atomic mass of lithium is 6.9241 u.

Explanation:

Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.

Formula used to calculate average atomic mass follows:

$\text{Average atomic mass }=\sum_{i=1}^n\text{(Atomic mass of an isotopes)}_i\times \text{(Fractional abundance})_i$ ....(1)

For $_3^6\textrm{Li}$ isotope:

Mass of $_3^6\textrm{Li}$ isotope = 6 u

Percentage abundance of $_3^6\textrm{Li}$ isotope = 7.59 %

Fractional abundance of $_3^6\textrm{Li}$ isotope = 0.0759

For $_3^7\textrm{Li}$ isotope:

Mass of $_3^7\textrm{Li}$ isotope = 7 u

Percentage abundance of $_3^7\textrm{Li}$ isotope = 92.41%

Fractional abundance of $_3^7\textrm{Li}$ isotope = 0.9241

Putting values in equation 1, we get:

$\text{Average atomic mass of Lithium}=[(6\times 0.0759)+(7\times 0.9241)]$

$\text{Average atomic mass of Lithium}=6.9241u$

Hence, the average atomic mass of lithium is 6.9241 u.

7 0

3 years ago

A student requires 2.00 L of 0.100 M NH4NO3 from a 1.75 M NH4NO3 stock solution. What is the correct way to get the solution?

Sonbull [250]

Answer: Measure 114 mL of the 1.75 M solution, and dilute it to 2.00 L.

Explanation:

The number of moles in the solution will remain same on dilution and thus according to Molarity Equation:

$M_1V_1=M_2V_2$

$M_1$ = molarity of first solution

$V_1$ = Volume of first solution

$M_2$ = molarity of second solution

$V_2$ = Volume of second solution

$0.1\times 2.00L=1.75M\times V_2$

$V_2=0.114L=114ml$

Thus 114 ml of 1.75 M solution is taken and the volume is diluted to 2.0 L to make 0.100 M solution.

3 0

3 years ago

Read 2 more answers

Which element is always found in impure form

Bezzdna [24]

C hydroyen
its aht plants breath

7 0

4 years ago

Read 2 more answers

Can Magnesium hydroxide be used as the base for this titration? Why or why not? 5. Describe the procedure that you will follow t

kvasek [131]

Explanation:

A.

Yes

B.

2KHP + Mg(OH)2 = 2KOH + Mg(HP)2

KHP is an acidic salt which reacts with Mg(OH)2 which is a base via double displacement/decomposition reaction.

C.

• One approach is to prepare the solution volumetrically using KHP crystals.

• Preparing 1 liter of 0.1 M KHP you would add 0.1 moles of KHP

Molar mass of KHP(C8H5KO4)

= (12*8) + (5*1) + 39 + (16*4)

= 204 g/mol

Number of moles = mass/molar mass

= 20.4/204

= 0.1 mol.

• This is added to a 1 liter volumetric flask, add deionized water until near the fill line, stopper and mix

D.

Number of moles = molar concentration * volume

= 0.025 * 0.100

= 0.0025 mol

Equation for the reaction:

Ba(OH)2 + 2KHP --> Ba(KP)2 + 2H2O

1 mole of Ba(OH)2 reacted with 2 moles of KHP. By stoichiometry,

Number of moles of Ba(OH)2 = 0.0025/2

= 0.00125 mol.

Molarity = number of moles/volume

= 0.00125/0.01

= 0.125 M of Ba(OH)2.

4 0

3 years ago

Naturally occurring boron has an atomic weight of 10.811. Its principal isotopes are 10B and 11B. Part A What is the abundance (

Darya [45]

Answer:

10B has 18.9%

11B has 81.1%

Explanation:Please see attachment for explanation

4 0

4 years ago