Answer:
HCl is the limiting reactant. It will completely be consumed (1.37 moles)
Option D is correct
Explanation:
Step 1: Data given
Mass of Zinc (Zn) = 50.0 grams
Mass of Hydrogen chloride (HCl) = 50.0 grams
atomic mass Zn = 65.38 g/mol
Molar mass HCl = 36.46 g/mol
Step 2: The balanced equation
Zn + 2HCl → ZnCl2 + H2
Step 3: Calculate moles
Moles = mass / molar mass
Moles Zn = 50.0 grams / 65.38 g/mol
Moles Zn = 0.764 moles
Moles HCl = 50.0 grams / 36.46 g/mol
Moles HCl = 1.37 moles
Step 4: Calculate limiting reactant
For 1 mol Zn we need 2 moles HCl to produce 1 mol ZnCl2 and 1 mol H2
HCl is the limiting reactant. It will completely be consumed (1.37 moles)
Zn is in excess. There will react 1.37/2 = 0.685 moles
There will remain 0.764 -0.685 = 0.079 moles
Answer:
The two ice sheets on Earth today cover most of Greenland and Antarctica. During the last ice age, ice sheets also covered much of North America and Scandinavia. Together, the Antarctic and Greenland ice sheets contain more than 99 percent of the freshwater ice on Earth.
Hope this helps! (:
The freezing point depression is a colligative property, which means that it depends on the number of particles of solute disolved in the solution.
When you have solutes that are ionic compounds they dissociate in water into ions, then the compound that dissociates more ions will produce more particles and will decrease the freezing point the most.
Given theses aqueous solutions Na2 CO3, Co Cl3, and Li NO3 you can predict the order of the freezing points.
First, write the dissociation equations>
Na2CO3 -> 2Na(+) + CO3 (2-) These are 3 ions: two of Na(+) and one of CO3(2-)
The number inside parenthesis are number of charge not number of molecules.
Co Cl3 -> Co(3+) + 3 Cl (1-) Those are 4 ions: one of Co (+) and three of Cl (-)
Li NO3 -> Li (+) + NO3 (-) those are two ions: one of Li (+) and one of NO3(-)
Then the ionic compound that dissociates into more ions give the solution with lower freezing point, and these is the rank from higher to lower freezing point:
Li NO3 > Na2 CO3 > Co Cl3.
Answer:
Explanation:
To convert from representative particles to moles, Avogadro's Number: 6.02*10²³, which tells us the number of particles (atoms, molecules, etc.) in 1 mole of a substance.
We can use it in a ratio.
Multiply by the given number of molecules.
Flip the ratio so the molecules of water cancel out.
Divide.
The original number of molecules has 2 significant figures: 3 and 1, so our answer must have the same. For the number we calculated, that is the tenth place. The 4 in the hundredth place tells us to leave the 1.
There are about 5.1 moles of water in 3.1*10²⁴ molecules of water.
Answer:
Rubidium-85=61.2
Rubidium-87=24.36
Atomic Mass=85.56 amu
Explanation:
To find the atomic mass, we must multiply the masses of the isotope by the percent abundance, then add.
<u>Rubidium-85 </u>
This isotope has an abundance of 72%.
Convert 72% to a decimal. Divide by 100 or move the decimal two places to the left.
- 72/100= 0.72 or 72.0 --> 7.2 ---> 0.72
Multiply the mass of the isotope, which is 85, by the abundance as a decimal.
- mass * decimal abundance= 85* 0.72= 61.2
Rubidium-85=61.2
<u>Rubidium-87</u>
This isotope has an abundance of 28%.
Convert 28% to a decimal. Divide by 100 or move the decimal two places to the left.
- 28/100= 0.28 or 28.0 --> 2.8 ---> 0.28
Multiply the mass of the isotope, which is 87, by the abundance as a decimal.
- mass * decimal abundance= 87* 0.28= 24.36
Rubidium-87=24.36
<u>Atomic Mass of Rubidium:</u>
Add the two numbers together.
- Rb-85 (61.2) and Rb-87 (24.36)
