Answer:
Si, Sn, Cs
Explanation:
Atomic no. Atomic radius
Silicon Si_______14___________0.117
Tin Sn______50___________0.140
cesium Cs______55___________0.262
Silicon is the smallest among these
Answer:
A. endothermic.
A. Yes, absorbed.
Explanation:
Let's consider the following thermochemical equation.
2 HgO(s) ⇒ 2 Hg(l) + O₂(g) ΔH = 182 kJ
The enthalpy of the reaction is positive (ΔH > 0), which means that the reaction is endothermic.
182 kJ are absorbed when 2 moles of HgO react (molar mass 216.59 g/mol). The heat absorbed when 72.8 g of HgO react is:
C. both a and b
If a light bulb can last longer with the same amount of energy it is given, that means it can use less energy to do the same job compared to one that does not last longer with the same amount of energy it is given. It is much like how a more fuel efficient car will be able to go farther on the same tank of gas, but if you pair it with a car that doesn't have as great of an mpg, when they go the same distance, the car with the greater mpg spends less fuel.
If you don't have to use the energy when you aren't utilizing it, then you can conserve the energy for when you do need it.
Answer:
4.00 is the pH of the mixture
Explanation:
The ethyl amine reacts with HNO3 as follows:
C2H5NH2 + HNO3 → C2H5NH3⁺ + NO3⁻
To solve this question we need to find the moles of ethyl amine and the moles of HNO3:
<em>Moles C2H5NH2:</em>
0.0500L * (0.100mol/L) = 0.00500 moles ethyl amine
<em>Moles HNO3:</em>
0.201L * (0.025mol/L) = 0.005025 moles HNO3
That means HNO3 is in excess. The moles in excess are:
0.005025 moles HNO3 - 0.00500 moles ethyl amine =
2.5x10⁻⁵ moles HNO₃
In 50 + 201mL = 251mL = 0.251L:
2.5x10⁻⁵ moles HNO₃ / 0.251L = 9.96x10⁻⁵M = [H+]
As pH = -log [H+]
pH = -log 9.96x10⁻⁵M
pH = 4.00 is the pH of the mixture
