<span>12.4 g
First, calculate the molar masses by looking up the atomic weights of all involved elements.
Atomic weight manganese = 54.938044
Atomic weight oxygen = 15.999
Atomic weight aluminium = 26.981539
Molar mass MnO2 = 54.938044 + 2 * 15.999 = 86.936044 g/mol
Now determine the number of moles of MnO2 we have
30.0 g / 86.936044 g/mol = 0.345081265 mol
Looking at the balanced equation
3MnO2+4Al→3Mn+2Al2O3
it's obvious that for every 3 moles of MnO2, it takes 4 moles of Al. So
0.345081265 mol / 3 * 4 = 0.460108353 mol
So we need 0.460108353 moles of Al to perform the reaction. Now multiply by the atomic weight of aluminum.
0.460108353 mol * 26.981539 g/mol = 12.41443146 g
Finally, round to 3 significant figures, giving 12.4 g</span>
The heat cause 300g water temperature increase from 20 to 26 celcius. The heat transferred would be: 300g * (26 °C -20 °C) *4.2 joule/gram °C= 7560J
The unknown substance is added to the water, so its final temperature should be the same as the water. The calculation would be:
7560J= 124g * (100-26)* specific heat
specific heat= 7560J / 124g / 74 °C= 0.8238 J/gram °C
a thin solid glass rod that is used in chemistry to combine substances. A stirring rod often has rounded ends and is about the length of a long straw.
<h3>What use serves the stirring rod?</h3>
A crucial component of lab apparatus for mixing chemicals and liquids for reactions is a long, thin stirring rod. Stirring rods are made of solid plastic, glass, or steel and are non-abrasive, chemically inert, and chemically resistant.
<h3>What is the name of the glass stirring rod?</h3>
Glass rod, also known as a stirring rod, stir rod, or solid glass rod, is frequently made of quartz and borosilicate glass. Its diameter and length can be modified to meet your needs.
<h3>Does filtration employ stirring rods?</h3>
When the liquid transfer procedure is paused, use a stirring rod to direct the liquid flow into the funnel and stop small amounts of liquid from dribbling down the beaker's outside.
learn more about stirring rod here
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Answer:
A) 0.95 mol
Explanation:
We will assume the gas given off in the fermentation is an ideal gas because that allows us to use the ideal gas equation.
PV = nRT
First let's convert all measurements to units that we can use
P = 702 mmHg * 1 atm/760 mmHg = 0.92368 atm
V = 25.0 L
R = 0.08206 L-atm/mol-K
T = 22.5 °C +273.15 = 295.65 K
PV = nRT
0.92368 atm * 25.0 L = n * 0.08206 L-atm/mol-K * 295.65 K
n = 0.9518 mol
