Answer:
6 x 10⁶ g Fe
Explanation:
Step 1: Set up dimensional analysis
7 x 10²⁸ atoms Fe (1 mol Fe/6.02 x 10²³ atoms Fe)(55.85 g Fe/1 mol Fe)
Step 2: Multiply, divide, and cancel out units
atoms Fe and atoms Fe cancel out.
mol Fe and mol Fe cancel out.
We should be left with g Fe.
7 x 10²⁸/6.02 x 10²³ = 116279 mol Fe
116279(55.85) = 6.49 x 10⁶ g Fe
Step 3: Sig figs
There is only 1 sig fig in this problem.
6.49 x 10⁶ g Fe ≈ 6 x 10⁶ g Fe
The SI base unit for length is meter.
In order to make smaller measurements, you can use the centi-, milli-, micro-, etc. prefixes.
When you want to reference larger measurements, you can use the kilo-, mega-, giga- and prefixes such as those.
Answer: The pressure required is 0.474 atm
Explanation:
Boyle's Law: This law states that pressure is inversely proportional to the volume of the gas at constant temperature and number of moles.
(At constant temperature and number of moles)
The equation is,
where,
= initial pressure of gas = 1.0 atm
= final pressure of gas = ?
= initial volume of gas = 
= final volume of gas = 
(
Now put all the given values in the above equation, we get:
The pressure required is 0.474 atm
Increasing temperatures in a reaction increases the kinetic energy of the reactant molecules. This causes them to move fast and hence collide with a higher frequency. The higher the rate of collision between the molecules, the faster the reaction.
Answer:
plaster is important because of the many uses you can make out of plaster
