The reactions that will take place will generate Zinc salts that will
taint the food. Excessive levels of these salts can cause sickness, so
it is very important to ensure food hygiene standards are met by keeping
acidic foods away from damaging materials like zinc that will erode and
get into the food.
Answer:
It is not water absorbant and also the colour black, due to it's dark nature makes the person wearing the cloth feel hot. Unlike cotton, silk is not at all water absorbant as it does not absord any sweat produced in the wearers body
Answer:
The molar concentration of Cu²⁺ in the initial solution is 6.964x10⁻⁴ M.
Explanation:
The first step to solving this problem is calculating the number of moles of Cu(NO₃)₂ added to the solution:

n = 1.375x10⁻⁵ mol
The second step is relating the number of moles to the signal. We know the the n calculated before is equivalent to a signal increase of 19.9 units (45.1-25.2):
1.375x10⁻⁵ mol _________ 19.9 units
x _________ 25.2 units
x = 1.741x10⁻⁵mol
Finally, we can calculate the Cu²⁺ concentration :
C = 1.741x10⁻⁵mol / 0.025 L
C = 6.964x10⁻⁴ M
A metal rail rusting in damp weather.