Answer:
223 g O₂
Explanation:
To find the mass of oxygen gas needed, you need to (1) convert moles Al to moles O₂ (via the mole-to-mole ratio from reaction coefficients) and then (2) convert moles O₂ to grams O₂ (via the molar mass). When writing your ratios/conversions, the desired unit should be in the numerator in order to allow for the cancellation of the previous unit. The final answer should have 3 sig figs because the given value (9.30 moles) has 3 sig figs.
4 Al + 3 O₂ ----> 2 Al₂O₃
^ ^
Molar Mass (O₂): 32.0 g/mol
9.3 moles Al 3 moles O₂ 32.0 g
------------------- x --------------------- x -------------------- = 223 g O₂
4 moles Al 1 mole
Answer:
Explanation:
How many mols do you have?
1 mol = 6.02 * 10^23 atoms
x mol = 6.25 * 10 ^32 atoms
1/x = 6.02*10^23 / 6.25 * 10^32 Cross multiply
6.02 * 10^23 * x = 1 * 6.25 * 10^32 Divide by 6.02 * 10^23
x = 6.25 * 10*32/ 6.02 ^10^23
x = 1.038 * 10^9 mols which is quite large.
Find the number of grams. (Use the value for copper on your periodic table. I will just use an approximate number.)\
1 mol of copper = 63 grams.
1.038 * 10^9 mols of copper = x
1/1.038 * 10^9 = 63/x Cross multiply
x = 1.038 * 10^9 * 63
x = 6.54 * 10^10 grams of copper.
Hello!
When the final velocity is less than the initial velocity, this is deceleration
<h2>
Why?</h2>
Acceleration is defined as the physical magnitude that measures the change in velocity with time. The units to express acceleration are speed over time.
The equation for acceleration is: 
Where: a=acceleration, v=final velocity, vo=initial velocity, t=final time, to=initial time.
If the final velocity is less than the initial velocity, then the acceleration is negative, and that is called deceleration. An example of this is when a car brakes.
Have a nice day!
