Answer:
8.8g of Al are necessaries
Explanation:
Based on the reaction, 2 moles of Al are required to produce 3 moles of hydrogen gas.
To solve this question we must find the moles of H2 in 11L at STP using PV = nRT. With these moles we can find the moles of Al required and its mass as follows:
<em>Moles H2:</em>
PV = nRT; PV/RT = n
<em>Where P is pressure = 1atm at STP; V is volume = 11L; R is gas constant = 0.082atmL/molK and T is absolute temperature = 273.15K at STP</em>
Replacing:
1atm*11L/0.082atmL/molK*273.15K = n
n = 0.491 moles of H2 must be produced
<em />
<em>Moles Al:</em>
0.491 moles of H2 * (2mol Al / 3mol H2) = 0.327moles of Al are required
<em />
<em>Mass Al -Molar mass: 26.98g/mol-:</em>
0.327moles of Al * (26.98g / mol) = 8.8g of Al are necessaries
Answer:
0.302L
Explanation:
<em>...97.1mL of 1.21m M aqueous magnesium fluoride solution</em>
<em />
In this problem the chemist is disolving a solution from 1.21mM = 1.21x10⁻³M, to 389μM = 389x10⁻⁶M. That means the solution must be diluted:
1.21x10⁻³M / 389x10⁻⁶M = 3.11 times
As the initial volume of the original concentration is 97.1mL, the final volume must be:
97.1mL * 3.11 = 302.0mL =
0.302L
Answer:
A.)
Explanation:
A change in state may seem like a chemical reaction, but it is actually a physical change. "A change in state" is basically saying that the appearance of whatever the item is, is taking a change physically. Whether this item was going through some examples of a physical change, which would be:
<em>melting (solid to liquid), evaporation (liquid to gas), condensation (gas to liquid), freezing (liquid to solid), deposition (gas to solid), and sublimation (solid to gas).</em>
A change in color, odor, taste, chemical compound, and temperature all represent a chemical reaction, because these are all things that are happening within the the item that is being given the product of a chemical change.
Think of it this way: <em>internal changes within the product: chemical. External changes within the product: physical.</em>
I hope this helps.
The two forms of oxygen, O2 and O3 is "<span>They have different molecular structures and different properties."</span>
The terms of a equation, the momentum of an object is equal to the mass of the object times the velocity of the object. where m is the mass and v is the velocity
