The elemental symbol of gold is denoted on the periodic table as being Au.
Answer:
c. add coefficients as needed
Explanation:
A chemical equation is defined as the equation that shows changes in a chemical reaction. A chemical equation consist of reactant and product, reactant is at left side of the arrow and product is at right side of the arrow.
Reactant => Product
While balancing a chemical equation, the basic rule is to balance the coefficient as required. Coefficient represents the number of molecules and is used at front of a chemical symbol. Change in coefficient helps balance the number of atoms or molecules of the substances on both the sides of the arrow.
Subscripts are never allowed to change because it can change the chemical involved in the reaction.
Hence, the correct answer is "c. add coefficients as needed".
Explanation:
Percentage ethylene by weight = 57%
Percentage propylene by weight = 43%
Suppose in 100 grams of polymer:
Mass of ethylene = 57 g
Mass of propylene = 43 g
Moles of ethylene = 
Moles of propylene = 
1 mole =
molecules/ atoms
Units of ethylene = 
Units of propylene = 
a) Fraction of ethylene units:

b ) Fraction of propylene units:

Saliva's buffering capacity and flow of secretion are directly related to the rate and extent of demineralization. ... Saliva can act as a replenishing source and inhibit tooth demineralization during periods of low pH, while promoting tooth remineralization when the pH returns to a neutral state.
Answer:
Explanation:
The relation between equilibrium constant and Ecell is given below .
E⁰cell = (RT / nF ) lnK , F is faraday constant T is 273 + 25 = 298 K
E⁰cell = 1.46 - 1.21 = .25 V
n = 2
Putting the values
.25 = (8.314 x 298 lnK) / (2 x 96485 )
lnK = 19.47
K = 2.85 x 10⁸
2 )
Change in free energy Δ G
Δ G ⁰ = nE⁰ F
n = 4
E⁰ = .4 + .83 = 1.23 V
Δ G ⁰= 4 x 1.23 x 96485
= 474706 J / mol
3 )
E⁰cell = (RT / nF ) lnK
n = 2
1.78 = 8.314 x 298 lnK / 2 x 96485
lnK = 138.638
K = 1.62 x 10⁶⁰