Answer:
0.44g
Explanation:
Given parameters:
Mass of magnesium hydroxide = 0.645g
Solution
The balanced reaction equation is shown below:
Mg(OH)₂ → MgO + H₂O
From the equation above, we see that the number of atoms are conserved.
To find the mass of magnesium oxide produced, we find the number moles of the decomposed magnesium hydroxide first:
Molar mass of Mg(OH)₂ = 24 + 2(16+1) = 58g/mol
Number of moles of Mg(OH)₂ = 
= 
= 0.011mole
Now, from the balanced equaiton, we know that:
1 mole of Mg(OH)₂ produces 1 mole of MgO
Therefore, 0.011mole of Mg(OH)₂ will produce 0.011mole of MgO
so mass of MgO = number of moles of MgO x molar mass of MgO
Molar mass of MgO = 24 + 16 = 40g/mol
mass of MgO = 0.011 x 40 = 0.44g
Answer:
Density of copper = 8.9 g/cm³
The density of liquid mercury is 13.6 g/cm³ which means mercury is denser than copper so copper will float on liquid mercury.
Explanation:
Given data:
weight of copper metal = 1896 g
Dimensions of block = 8.4 cm, 5.5 cm, 4.6 cm
Density of copper = ?
Will it float to the liquid mercury = ?
Solution:
Density:
Density is equal to the mass of substance divided by its volume.
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
volume of coper metal = 8.4 cm × 5.5 cm × 4.6 cm
volume of coper metal =212.52 cm³
d = 1896 g/ 212.52 cm³
d = 8.9 g/cm³
The density of liquid mercury is 13.6 g/cm³ which means mercury is denser than copper so copper will float on liquid mercury.
Notice that the metals trade places. That means it is a double replacement RXN or C
Seven valence electrons are present in the 'Lewis structure' for the given chlorine atom
A Chlorine atom has total 17 electrons in total. In the 'first orbit' 2 electrons, 10 electrons in the 'second orbit' and finally 7 electrons in the last orbit. As Chlorine is a Group 7 element, chlorine will have 7 'valence electrons' in its outermost orbit. While drawing the 'Lewis structure' of Chlorine we shall put seven dots that is the electrons or valance electrons around the symbol of Chlorine (CI).
<h3>
What are Valence electrons ?</h3>
The electrons in an atom's outermost shell, or energy level, are called valence electrons. For instance, the valence electrons of oxygen are six, with two in the 2s subshell and four in the 2p subshell.
- An atom's outer shell electrons, known as valence electrons, can take role in the creation of chemical bonds. When two atoms establish a single covalent bond, normally both atoms contribute one valence electron to create a shared pair. The ground state of an atom is its state with the least amount of energy.
Learn more about Valence electron here:
brainly.com/question/371590
#SPJ4
Answer:
D
Explanation:
Al is a reducing agent because it removes Oxygen from another compound
Mno2 is an oxidizing agent
