Answer: 8.1e+2 or 8.1E+2 (in the scientific notation mode), based on that the number given is 8.1 × 10².
Explanation
Scientific calculators use the letter e or E to show the numbers in scientific notation mode.
These are some examples of numbers that require scientific notation and how they are shown.
Number Scientific calculator display
6.022 × 10²³ 6.022 e+23
5 × 10 -12 5 E -12
So, understanding that your question is about number 8.1 × 10², the scientific calculator could show 8e+2.
Nevertheless, since 8 .1 × 10² is 810, not a long number, if the display is not in scientific notation mode, it could just display just 810,
There are several information's already given in the question. Based on the information's provided, the answer can be easily deduced.
V1 = 25 ml
= 25/1000 liter
= 0.025 liter
V2 = 18 ml
= 18/1000 liter
= 0.018 liter
M2 = 1.0 M
M1 = ?
Then
M1V1 = M2V2
M1 = M2V2/V1
= (1 * 0.018)/0.025
= 0.72 M
From the above deduction, it can be easily concluded that the correct option among all the options that are given in the question is the first option or option "A". I hope that this is the answer that has actually come to your help.
The balanced chemical reaction is written as:
<span>4C(s) + S8(s) → 4CS2(l)
We are given the amount of carbon and sulfur to be used in the reaction. We need to determine first the limiting reactant to be able to solve this correctly.
</span>7.70 g C ( 1 mol / 12.01 g) =0.64 mol C
19.7 g S8 ( 1 mol / 256.48 g) = 0.08 mol S8
The limiting reactant would be S8. We use this amount to calculate.
0.08 mol S8 ( 4 mol CS2 / 1 mol S8 ) ( 256.48 g / 1 mol ) = 78.8 g CS2
Density is Mass divided by volume.
Answer:
The heat released by the combustion is 20,47 kJ
Explanation:
Bomb calorimeter is an instrument used to measure the heat of a reaction. The formula is:
Q = C×m×ΔT + Cc×ΔT
Where:
Q is the heat released
C is specific heat of water (4,186kJ/kg°C)
m is mass of water (1,00kg)
ΔT is temperature change (23,65°C - 20,45°C)
And Cc is heat capacity of the calorimeter (2,21kJ/°C)
Replacing these values the heat released by the combustion is:
<em>Q = 20,47 kJ</em>
