The formula on the periodate table is Rb
Answer:
Explanation:
The passage is all about temperature. Remember that it is an external piece of evidence.
When you say that a reaction is exothermic, what you are really saying is that when the bonds break, the energy created must be given away.
When you say the reaction of endothermic what you are saying is that the bonds will break only if the reaction can get heat from the environment and thus make the environment feel cooler.
The answer is therefore, B
Comment
I'm going to use rounded numbers to calculate the molar mass of water.
Water Molar Mass
- 2H = 2 * 1 = 2
- 1O = 1 * 16 = 16
- Molar Mass = 18 grams / mole
Moles of water
- given mass = 9.176 grams
- Molar Mass = 18 grams / mole
- moles = ??
Formula
moles = given mass / molar mass
moles = 9.176 / 18
moles 0.5098 Answer
1) Answer is: the hydrogen ion concentration is 1·10⁻¹ mol/L.
[OH⁻] = 1·10⁻¹³<span> mol/L, equilibrium concentration of hydroxide anion.
</span>[H⁺] is the concentration<span> of hydrogen ions.
</span>[OH⁻] · [H⁺] = 10⁻¹⁴ mol²/L², ionicproduct of water on room temperature.
[H⁺] = 10⁻¹⁴ mol²/L² ÷ 1·10⁻¹³ mol/L.
[H⁺] = 10⁻¹ mol/L = 0,1 mol/L.
2) pH = -log[H⁺], <span>approximately </span><span>the negative of the base 10 </span>logarithm<span> of the </span>molar concentration of hydrogen ions
pH = -log(10⁻¹ mol/L).
pH = 1.
This solution is acid, because pH value (potential of hydrogen) is less than seven. If pH is greater than seven, slotion is base and if pH is equal seven, solution is neutral.
I believe the answer is C. atomic structure and bonds.