2 is the significant figure in 0.025
Explanation:
Number of moles equal to the given mass divided by molar mass of the element or compound.
Mathematically, No. of moles = ![\frac{mass given}{Molar mass}](https://tex.z-dn.net/?f=%5Cfrac%7Bmass%20given%7D%7BMolar%20mass%7D)
The given mass is
g and molar mass is 24.30 g/mol.
Therefore, calculate the number of moles as follows.
No. of moles = ![\frac{mass given}{Molar mass}](https://tex.z-dn.net/?f=%5Cfrac%7Bmass%20given%7D%7BMolar%20mass%7D)
= ![\frac{4.86 \times 10^{4} g}{24.30 g/mol}](https://tex.z-dn.net/?f=%5Cfrac%7B4.86%20%5Ctimes%2010%5E%7B4%7D%20g%7D%7B24.30%20g%2Fmol%7D)
=
mol
=
mol
or, = 2000 mol
Thus, we can conclude that
g of Mg has 2000 moles.
Answer:
Volume of dry gas at STP = 0.432 liters or 432 ml
Explanation:
Given:
Pressure (P) = 740 mmHg - 24 mmHg = 716 mmHg
Temperature (t) = 25 degrees C + 273 K = 298 K
500 ml = 0.5 l
Find:
Volume of dry gas at STP
Computation:
[P1][V1] / T1 = [P2][V2] / T2
[716][0.5] / 298 K = [760][ x Liters] / 273 K
x = 0.432 Liters
Volume of dry gas at STP = 0.432 liters or 432 ml
Answer: 4
Explanation: The law of superposition states that in a sequence of rock layers, the youngest layer is on the top, and the oldest one is on the bottom, each being younger than the one beneath it and older than the one above it.
<u>Answer: </u>The correct answer is ![CH_4+2O_2\rightarrow CO_2+2H_2O+212,800Cal](https://tex.z-dn.net/?f=CH_4%2B2O_2%5Crightarrow%20CO_2%2B2H_2O%2B212%2C800Cal)
<u>Explanation:</u>
Exothermic reactions are defined as the reactions in which heat energy is released during a chemical reaction. In these reactions, energy of the products is less than the energy of the reactants.
for these reactions are ought to be negative.
In these chemical reactions, energy term is written on the product side.
From the given chemical reactions, only one reaction satisfies the above information. The chemical reaction is:
![CH_4+2O_2\rightarrow CO_2+2H_2O+212,800Cal](https://tex.z-dn.net/?f=CH_4%2B2O_2%5Crightarrow%20CO_2%2B2H_2O%2B212%2C800Cal)