Calculate the Kelvin temperatures of the water and record your answers in the data table.

During lab, a student used a Mohr pipet to add the following solutions into a 25 mL volumetric flask. They calculated the final

kompoz [17]

Answer:

(FeSCN⁺²) = 0.11 mM

Explanation:

Fe ( NO3)3 (aq) [0.200M] + KSCN (aq) [ 0.002M] ⇒ FeSCN+2

M (Fe(NO₃)₃ = 0.200 M

V (Fe(NO₃)₃ = 10.63 mL

n (Fe(NO₃)₃ = 0.200*10.63 = 2.126 mmol

M (KSCN) = 0.00200 M

V (KSCN) = 1.42 mL

n (KSCN) = 0.00200 * 1.42 = 0.00284 mmol

Total volume = V (Fe(NO₃)₃ + V (KSCN)

= 10.63 + 1.42

= 12.05 mL

Limiting reactant = KSCN

So,

FeSCN⁺² = 0.00284 mmol

M (FeSCN⁺²) = 0.00284/12.05

= 0.000236 M

Excess reactant = (Fe(NO₃)₃

n(Fe(NO₃)₃ = 2.126 mmol - 0.00284 mmol

=2.123 mmol

For standard 2:

n (FeSCN⁺²) = 0.000236 * 4.63

=0.00109

V(standard 2) = 4.63 + 5.17

= 9.8 mL

M (FeSCN⁺²) = 0.00109/9.8

= 0.000111 M = 0.11 mM

Therefore, (FeSCN⁺²) = 0.11 mM

7 0

3 years ago

Consider the neutralization reaction 2 HNO 3 ( aq ) + Ba ( OH ) 2 ( aq ) ⟶ 2 H 2 O ( l ) + Ba ( NO 3 ) 2 ( aq ) A 0.120 L sample

k0ka [10]

Answer:

The concentration of the HNO3 solution is 0.150 M

Explanation:

Step 1: Data given

Volume of the unknown HNO3 sample = 0.120 L

Volume of the 0.200 M Ba(OH)2 = 45.1 mL

Step 2: The balanced equation

2HNO3 + Ba(OH)2 ⟶ Ba(NO3)2 + 2H2O

Step 3: Calculate moles Ba(OH)2

moles Ba(OH)2 = molarity * volume

moles Ba(OH)2 = 0.200 M * 0.0451 L

moles Ba(OH)2 = 0.00902 moles

Step 4: Calculate moles of HNO3

For 1 mole of Ba(OH)2 we need 2 moles of HNO3

For 0.00902 moles of Ba(OH)2 we need 2*0.00902 = 0.01804 moles

Step 5: Calculate molarity of HNO3

molarity = moles / volume

molarity = 0.01804 / 0.120 L

Molarity = 0.150 M HNO3

The concentration of the HNO3 solution is 0.150 M

6 0

3 years ago

Wisdom teeth are the third and final set of human molars that come in during the late teens or early twenties. In some cases, th

Marina86 [1]

The answer is Vestigal. It is a type of anatomical structure that no longer serves any function. Over time they are no longer needed in the body. Apart from the wisdom tooth, another example would be the tail bone which has no use for humans.

5 0

3 years ago

Read 2 more answers

The compound adrenaline contains 56.79% c, 6.56% h, 28.37% o, and 8.28% n by mass. what is the empirical formula for adrenaline?

Phoenix [80]

To determine the empirical formula of the compound given, we need to determine the ratio of each element in the compound. To do that we assume to have 100 grams sample of the compound with the given composition. Then, we calculate for the number of moles of each element. We do as follows:
mass moles
C 56.79 4.73
H 6.56 6.50
O 28.37 1.77
N 8.28 0.59

Dividing the number of moles of each element with the smallest value, we will have the empirical formula:

 moles ratio
C 4.73 / 0.59 8
H 6.50 / 0.59 11
O 1.77 / 0.59 3
N 0.59 / 0.59 1

The empirical formula would be C8H11O3N.

8 0

3 years ago

A student sees a change in mass in the lab when mixing two chemicals what is a possible explanation?

Hitman42 [59]

Answer:

The mixing of two chemicals may result in the production of a gas which is lost to the air. This will reduce the mass of the chemical mixture, because mass is being lost in a gaseous form.

4 0

3 years ago