A beaker of black powder can be a mixture with different substances (i.e gunpowder: a mixture of sulfur, charcoal, etc.), an element which can probably be carbon (known as black), and a compound as well which can be potassium nitrate. Hence, the answer is D.
Answer:
A) Devices that transfer kinetic energy have a source of power that is in motion
Kinetic energy is the energy in motion, as such, a device that transfers kinetic energy transfers the energy the power source has into other energy forms
B) Kerosene does not easily cold start like diesel which can burn after compression
C) The first law of thermodynamics states that energy is conserved and it can neither be created nor destroyed, but can be changed from one form to another.
Therefore, when energy is not available in a given location or body, it cannot be obtained from that body or location
Explanation:
Answer:
Scandium is the smallest element of the four
Explanation:
Vanadium = 50.9415 u
Titanium = 47.867 u
Scandium = 44.955912 u
Chromium = 51.9961 u
Answer:
a) 2NaOH+H2SO4→Na2SO4+2H2O2NaOH+H2SO4→Na2SO4+2H2O
b) Số phân tử NaOH : Số phân tử H2SO4 = 2:1
Số phân tử NaOH : Số phân tử Na2SO4 = 2:1
Số phân tử NaOH : Số phân tử H2O = 2:2
Explanation:
Answer:
No
Explanation:
One mole of P₄ react with six moles of I₂ and gives 4 moles of PI₃.
When one gram phosphorus and 6 gram of iodine react they gives 8.234 g
ram of PI₃ .
Given data:
Mass of phosphorus = 1 g
Mass of iodine = 6 g
Mass of PI₃ = ?
Solution:
Chemical equation:
P₄ + 6I₂ → 4PI₃
Number of moles of P₄:
Number of moles = Mass /molar mass
Number of mole = 1 g / 123.9 g/mol
Number of moles = 0.01 mol
Number of moles of I₂:
Number of moles = Mass /molar mass
Number of moles = 6 g / 253.8 g/mol
Number of moles = 0.024 mol
Now we will compare the moles of PI₃ with I₂ and P₄.
I₂ : PI₃
6 : 4
0.024 :
4/6×0.024 = 0.02
P₄ : PI₃
1 : 4
0.01 : 4 × 0.01 = 0.04 mol
The number of moles of PI₃ produced by I₂ are less it will be limiting reactant.
Mass of PI₃ = moles × molar mass
Mass of PI₃ = 0.02 mol × 411.7 g/mol
Mass of PI₃ = 8.234 g