Answer:
296.448 g
Explanation:
Density:
we know that density of an object can be measured by dividing its mass to its volume.
Symbol:
The symbol used for density is called rho. It is represented by ρ. However letter D can also be used to represent the density.
Units:
SI unit of density is Kg/m3.
Other units are given below,
g/cm3, g/mL , kg/L
Formula:
D=m/v
D= density
m= mass
V= volume
Given data:
volume= 1.2 cm x 4.00 cm x 3.20 cm =15.36 cm3
density= 19.3 g/cm3
mass=?
Now we will put the values in the formula,
d=m/v
d x V= m
m = 15.36 cm3 x 19.3 g/cm3
m=296.448 g
so the mass of block of gold is 296.448 g
Answer:
The correct option is: 2.50 g
Explanation:
Reaction involved: Mg(s) + 2 HCl(aq) → MgCl₂(aq) + H₂(g)
Molar mass: Mg = 24.305 g/mol, HCl = 36.461 g/mol
In the given reaction, 1 mole Mg reacts with 2 moles HCl.
Given: mass of HCl = 7.50 g
So, the number of moles of HCl = given mass ÷ molar mass = 7.50 g ÷ 36.461 g/mol = 0.2057 moles
Therefore, the<u> number of moles of Mg</u> that reacts with 0.2057 mole HCl = 0.2057 ÷ 2 = 0.1028 moles
Therefore, <u>the mass of Mg in grams</u> = molar mass × number of moles = 24.305 g/mol × 0.1028 mole = 2.5 g
In electrophilic aromatic substitution reactions the hydroxyl group is an o,p-director because: hydroxyl group donates the electron density to the ring by induction and destabilizes the meta sigma complex and by resonance and it stabilizes the ortho and para sigma complexes of aromatic ring .
Most ring activators have atoms with unshared electron pairs directly attached to a carbon atom of the benzene ring . For example, the — OH group has two pairs of unshared electrons on the oxygen atom , which will form a bond to a carbon atom of the benzene ring . Thus , the — OH group will be an activating group in electrophilic aromatic substitution reactions .
to learn more about electrophilic aromatic substitution reactions please click here ,
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Answer:
in a sold the particles are in a fixed position and can only vibrate on the spot but when it changes into a liquid the energy is used to weaken the bonds so there are weak forces of attraction between the particles, all particles are still touching each other but are now free to move around. Ina gas all the bonds are broken, the gas particles are free to move around anywhere and the more collisions there are, the more the pressure increases
No. of moles in 134g of Mg, n=134/24 =5.58 moles
No. of atoms = n* Avogadro number
= 5.58 X 6.022 X 10^23
=33.60 X 10^23 atoms
