Answer: The answer is S = 0.1528 cal/g °C
Explanation:
By the law of conservation of energy, energy is neither created nor destroyed.
So, energy lost by metal pieces is equal to the energy gained by water in the calorimeter.
Specific heat of water is 1 cal/g °C
⇒ heat energy Q = mSΔT, where m = mass of a substance
S = specific heat
ΔT = change in temperature
Now, the heat lost by metal piece, Q = 72×S×(96-31)
= 4680×S cal
Heat gained by water, Q = 130×1×(31-25.5)
= 715 cal
⇒ 4680×S = 715.
⇒ S = 0.1528 cal/g °C.
The Calcium atom has 2 valence electrons but a Calcium ion will have no electrons because it is a cation ion. Meaning that there are more protons than electrons. Also, the normal calcium symbol is Ca but the calcium ion is Ca²⁺
I hope this wasn't too late
Answer:
1.) AgNO₃
2.) 0.563 moles AgBr
Explanation:
The limiting reagent is the reagent that is used up completely during a reaction. It can be identified by calculating which reactant produces the smallest amount of product. This can be done by determining the number of moles of each reagent (via molarity conversion). and then converting it to moles of the product (via mole-to-mole ratio).
AgNO₃ (aq) + KBr (aq) ---> AgBr (s) + KNO₃ (aq)
Molarity (M) = moles / liters
100 mL = 1 L
AgNO₃
45.0 mL / 100 = 45.0 L
1.25 M = ? moles / 0.450 L
? moles = 0.563 moles
KBr
75.0 mL / 100 = 0.750 L
0.800 M = ? moles / 0.750 L
? moles = 0.600 moles
In this case, there is no need to use the mole-to-mole ratio because all of the coefficients are one in the reaction (the amount of the limiting reagent used is the same amount of product produced). Since AgNO₃ produces the smaller amount of product, it is the limiting reagent.
Answer:
2.03 moles of Gold
Explanation:
Gold is one of the most precious metal metal used in many applications and mainly as a jewellery. In terms of purity it is categorized in Karats. 24 Karat is considered the purest Gold (i.e. 100 % Gold) while other Karats (14, 18, 22 e.t.c) are alloys with other metals and gyms.
Data Given:
Mass of Gold = 400 g
A.Mass of Gold = 196.97 g.mol⁻¹
Calculate Moles of Gold as,
Moles = Mass ÷ M.Mass
Putting values,
Moles = 400 g ÷ 196.97 g.mol⁻¹
Moles = 2.03 moles of Gold
