Answer:
The mass percentage of bromine in the original compound is 81,12%
Explanation:
<u>Step 1: Calculate moles AgBr</u>
moles AgBr = mass AgBr / molar mass AgBr
= 0.8878 g / 187.77 g/mol
= 0.00472812 moles AgBr
⇒
Since 1 mol AgBr contains 1 mol Br-
Then the amount of moles Br- in the original sample must also have been 0.00472812 moles
<u>Step 2:</u> Calculating mass Br-
mass Br- = molar mass Br x moles Br-
= 79.904 g/mol x 0.00472812 mol
= 0.377796 g Br-
⇒
There were 0.377796 g Br- in the original sample
<u>Step 3:</u> Calculating mass percentage Br-
⇒mass percentage = actual mass Br- / total mass x 100%
% mass Br = 0.377796 g / 0.4657 g x 100 %
= 81.12%
Answer:
A source of electricity, a wire coil, and an iron core
Explanation:
An electromagnet has three critical components:
1. A source of electricity
This is often a battery.
It generates the electric current that produces the magnetic field.
2. A wire coil
The wire carries the electric current.
Stacking the wire into loops makes a stronger magnetic field.
The more loops in the coil, the stronger the field.
3. An iron core
An iron core greatly increases the strength of the magnetic field within it and at its ends.
2.67 is the hsjshkahsjahsgz hi ajahsghsjahaysjs
<span>when it comes to adding or subtracting numbers, his final answer should have the same number of decimal places as the least precise value.
For example if you add 2 numbers; 10.443 + 3.5 , 10.443 has 3 decimal places and 3.5 has only one decimal place.
Therefore 3.5 is the less precise value.
So when adding these 2 values the final answer should have only one decimal place.
after adding we get 13.943 but it can have upto one decimal place. then the second decimal place is less than 5 so the answer should be rounded off to 13.9.
the answer is the same number of decimal places as the least precise value</span>
Answer:
36
Explanation:
Since the sample was undiluted the number of colonies is the number that grew on the nutrient agar which is 36 colonies. If it was diluted for example let say 0.1 ml from a dilution in which 1 ml of the sample was added to 9 ml of water, and it grew colonies then 0.1 ml yielded 6 colonies, 1 ml of the diluted sample will yield 60 colonies and 10 ml will have 600 colonies and therefore the 1 ml undiluted sample will have 600 colonies.
