Answer:
Supongo que su suma 81632 + 2800 = 84432, por lo que la distancia que logró mover el objeto fue 2800.
Explanation:
Solids- wood, sand, brick, rock
Liquids- water, milk, blood, coffee
Gases- air, helium, nitrogen, hydrogen
Answer:
The answers are in the explanation
Explanation:
A buffer is the mixture of a weak acid with its conjugate base or vice versa. Thus:
<em>1)</em> Mixing 100.0 mL of 0.1 M HF with 100.0 mL of 0.05 M mol KF. <em>Will </em>result in a buffer because HF is a weak acid and KF is its conjugate base.
<em>2)</em> Mixing 100.0 mL of 0.1 M NH₃ with 100.0 mL of 0.1 M NH₄Br. <em>Will not </em>result in a buffer because NH₃ is a strong base.
<em>3) </em>Mixing 100.0 mL of 0.1 M HCN with 100.0 mL of 0.05 M KOH. <em>Will </em>result in a buffer because HCN is a weak acid and its reaction with KOH will produce CN⁻ that is its conjugate base.
<em>4)</em> Mixing 100.0 mL of 0.1 M HCl with 100.0 mL of 0.1 M KCl <em>Will not </em>result in a buffer because HCl is a strong acid.
<em>5)</em> Mixing 100.0 mL of 0.1 M HCN with 100.0 mL of 0.1 M KOH <em>Will not </em>result in a buffer because each HCN will react with KOH producing CN⁻, that means that you will have just CN⁻ (Conjugate base) without HCN (Weak acid).
I hope it helps!
Answer : B) In step 2, there was a chemical change which was observed in sugar.
Explanation : In A step 2 there was a physical change that was seen. By just boiling the dissolved salt solution salt was obtained. Therefore, it is a physical change. In B step 2 there was a chemical change seen as sugar solution was thickened and turned brown. It was not obtained in its original form; there was a chemical reaction that took place during sugar evaporation. As chemical change is the one where the reaction is irreversible.
Therefore only in B step 2 there was a chemical change that was observed.
Answer:
151 g/mol
Explanation:
In order to solve this problem we need to keep in mind the formula for the <em>boiling point elevation</em>:
Where:
- ΔT is the temperature difference between the boiling point of the solution and that of pure water. 100.37 °C - 100.00 °C = 0.37 °C.
- <em>m</em> is the molarity of the solution
- i is the van't Hoff factor. As the solute is a nonelectrolyte, the factor is 1.
Input the data and <u>calculate </u><em><u>m</u></em>:
- 0.37 °C = 0.51 °C/m * <em>m</em> * 1
We now can <u>calculate the number of moles of the substance</u>, using the <em>definition of molarity</em>:
- molarity = moles of solute / kg of solvent
In this case kg of solvent = 90.0 g / 1000 = 0.090 kg
- 0.72 m = moles / 0.090 kg
Finally we <u>calculate the molar mass</u>, using the <em>number of moles and the mass</em>:
- 9.81 g / 0.065 mol = 151 g/mol
