Answer:
2NaBr + I2 Right arrow. 2NaI + Br2
2AgNO3 + Ni Right arrow. Ni(NO3)2 + 2Ag
Explanation:
The activity or electrochemical series is an arrangement of elements according to their order
of reactivity.
If we look at the reactions, one thing that we must note is that the reactions that can occur are those in which an element that is higher in the series displaces another element that is lower in the series.
Br is higher in the electrochemical series than I so it can displace it. Ni is higher than Ag in the electrochemical series hence it can displace it.
Answer:
126.4 g of 
are required
Explanation:
Balanced reaction: 
According to balanced reaction-
8 moles of 
are produced from 2 moles of
So, 8.70 moles of are produced from 
moles of or 2.175 moles of
Molar mass of = 58.12 g/mol
So, mass of required = 
= 126.4 g
Hence 126.4 g of are required
<span>1.15x10^24 molecules of hypothetical substance b
Making the assumption that each molecule in hypothetical substance a reacts to produce a single molecule of hypothetical substance b, then the number of molecules of substance b will be the number of moles of substance a multiplied by avogadro's number. So
Moles hypothetical substance a = 29.9 g / 15.7 g/mol = 1.904458599 moles
This means that we should also have 1.904458599 moles of hypothetical substance b. And to get the number of atoms, multiply by 6.0221409x10^23, so:
1.904458599 * 6.0221409x10^23 = 1.146892x10^24 molecules.
Rounding to 3 significant figures gives 1.15x10^24</span>
Answer:
how strong it is
Explanation:
Seismographs are not able to say when earthquake will happen, but they help humans to know how strong it is or if it is happening or not
