0.0857
Rounding off to three digits
Since 7 is more than five you change it to 0 and add 1 to 5
A: 0.086
<span>The "second" is the SI base unit of time.</span>
Answer:
preservation of raw materials
Explanation:
Reusing and recycling is the process by which the used products are used again or recycled in different form to use it again. Excessive use of the raw materials can lead to their extinction. Recycling the materials helps in decreasing the pollution in the environment. It also helps in reduction in the emission of the harmful gases. When municipal wastes are reused or recycled, the raw materials are preserved. These are the process involved in sustainable use of resources.
<span>9.40x10^19 molecules.
The balanced equation for ammonia is:
N2 + 3H2 ==> 2NH3
So for every 3 moles of hydrogen gas, 2 moles of ammonia is produced. So let's calculate the molar mass of hydrogen and ammonia, starting with the respective atomic weights:
Atomic weight nitrogen = 14.0067
Atomic weight hydrogen = 1.00794
Molar mass H2 = 2 * 1.00794 = 2.01588 g/mol
Molar mass NH3 = 14.0067 + 3 * 1.00794 = 17.03052 g/mol
Moles H2 = 4.72 x 10^-4 g / 2.01588 g/mol = 2.34140921086573x10^-4 mol
Moles NH3 = 2.34140921086573x10^-4 mol * (2/3) = 1.56094x10^-4 mol
Now to convert from moles to molecules, just multiply by Avogadro's number:
1.56094x10^-4 * 6.0221409x10^23 = 9.400197448261x10^19
Rounding to 3 significant figures gives 9.40x10^19 molecules.</span>
Answer:
a)there would be no reaction
Explanation:
The activity series of metals has many functions. The one applicable to this problem is that it can be used to determine whether a reaction will occur or not. Also, based on the positions of metals in the series, we can know how reactive a metal is compared to another.
In a single displacement reaction, a metal replaces another metal based on their position on the activity series. Metals that are higher in the series are generally more reactive than others below them and so will displace them.
Would aluminum replace magnesium to form a new compound or would there be no reaction?
Magnesium is higher than aluminum in the activity series. Therefore it is more reactive than aluminum. No reaction will occur.
