Answer:
quantity of heat=mc*theta
=25*0.930(76-25)
=25*0.930*51
=1185.75J
=11.9kJ
Answer: no tea is not a pure substances
Explanation:
A Tea is a solution of compounds in water, so it is not chemically pure. It is usually separated from tea leaves by filtration. B Because the composition of the solution is uniform throughout, it is a homogeneous mixture. ... A Aluminum oxide is a single, chemically pure compound.Sep 18, 2019
Answer:
SeF4 is a polar molecule
Explanation:
SeF4 is a polar molecule because a polar molecule is any molecule that have lone pairs of electrons in the central atom or have atoms that are electronegative and the electrons between that are covalently bonded are not evenly distributed.
The electronegative atoms of flourine in SeF4 are not evenly distributed and kind pairs of electrons are on the central atom.
Answer: 406 hours
Explanation:

where Q= quantity of electricity in coloumbs
I = current in amperes = 39.5 A
t= time in seconds = ?
The deposition of copper at cathode is represented by:

Coloumb of electricity deposits 1 mole of copper
i.e. 63.5 g of copper is deposited by = 193000 Coloumb
Thus 19.0 kg or 19000 g of copper is deposited by =
Coloumb

(1hour=3600s)
Thus it will take 406 hours to plate 19.0 kg of copper onto the cathode if the current passed through the cell is held constant at 39.5 A