The copper wire was sanded before burning in order to make sure that copper metal was exposed on the surface of the wire.
Answer: B
Explanation
The copper wire when placed in atmosphere without coating leads to oxidation of copper metal with respect to the impurities present in the atmosphere.
As copper is electropositive in nature, so electronegative ions present in the universe will try to react with copper and the copper will react easily with other elements.
So generally copper wire is coated with color or polymer coating.
In this case, the copper wire without any coating is sanded, so that the eddy sheets or polishing materials on friction with copper wire will remove the impurities by the electrostatic law of conservation of charges and charge transfer.
As the impurities are removed when copper wire is sanded, the copper atoms will be exposed on the surface of the wire leading to burning of copper in the copper wire.
The answer is d, hand soap.
Hand soap is alkaline and red litmus paper turns blue when exposed to alkaline solution.
Answer:
valency of an element is a combining power of an element.
for example oxygen has six valance electron but its valency is 2.
hope it helps.
Answer:
PNO₂ = 0.49 atm
PN₂O₄ = 0.45 atm
Explanation:
Let's begin with the equation of ideal gas, and derivate from it an equation that involves the density (ρ = m/V).
PV = nRT
n = m/M (m is the mass, and M the molar mass)


PxM = ρRT
ρ = PxM/RT
With the density of the gas mixture, we can calculate the average of molar mass (Mavg), with the constant of the gases R = 0.082 atm.L/mol.K, and T = 16 + 273 = 289 K

0.94Mavg = 63.9846
Mavg = 68.0687 g/mol
The molar mass of N is 14 g/mol and of O is 16 g/mol, than
g/mol and
g/mol. Calling y the molar fraction:

And,


So,





The partial pressure is the molar fraction multiplied by the total pressure so:
PNO₂ = 0.52x0.94 = 0.49 atm
PN₂O₄ = 0.48x0.94 = 0.45 atm
Answer:
0.384g/l
Explanation: the density version of the ideal gas law is pm=drt
in which p= pressure, m=molar mass,d=, density, r= to a constant which is 0.08206, and t=temperature so just input the values
PM=DRT. so to find d the formula would be D=RT\PM
D=<u>0.08206*242.5</u>
0.7311*70.90
D=0.384g/l