Answer:
60.02 g.
Explanation:
- It is clear from the balanced equation:
<em>Mg + 2HCl → MgCl₂ + H₂.
</em>
that 1.0 mole of Mg reacts with 2.0 moles of HCl to produce 1.0 mole of MgCl₂ and 1.0 moles of H₂.
- 20.0 g of Mg reacts with excess HCl. To calculate the no. of grams of HCl that reacted, we should calculate the no. of moles of Mg:
<em>no. of moles of Mg = mass/atomic mass</em> = (20.0 g)/(24.3 g/mol) = 0.823 mol.
- From the balanced equation; every 1.0 mol of Mg reacts with 2 moles of HCl.
∴ 0.833 mol of Mg will react with (2 x 0.833 mol = 1.646 mol) of HCl.
<em>∴ The mass of reacted HCl = no. of moles x molar mass</em> = (1.646 mol)(36.46 g/mol) = <em>60.02 g.</em>
We could (a) stir faster and (b) warm the mixture.
<em>Stirring faster</em> moves freshly-dissolved sugar away from the solid and allows new water molecules to contact with the surface,
<em>Warming the mixture</em> gives the water molecules more kinetic energy, so their collisions with the surface of the sugar will be more effective in removing the sugar molecules.
Answer:
D)groups 1 and 2
Explanation:
The s-block of elements are made up of those chemical elements we can find in groups 1 and 2 on the periodic table.
A periodic table of element is based on the periodic law which states that "the properties of elements are a periodic function of their atomic number".
In the table;
- elements having the same number of electrons in the outermost shell are placed over one another in vertical columns.
- each resulting vertical column is called a group or family.
- resulting horizontal rows are known as periods.
The s-block consists of elements in groups 1 and 2 having an outermost ""ns"" shell configuration. They are predominantly metals.
For Option A, groups 3-12 is the D-block
Option B, group 18 is filled with noble gases and it makes up the p-block
Option C, group 13-18 is makes up the p-block too.
So, the s-block is made up group 1 and 2 elements.
Answer;
4.5 m³
Solution:
The statement says that two blocks are present on a lid of a container with volume of 9 m³. The mass of lid is equal to the mass of two blocks. It means that initially there are four blocks (or four atm pressure) upon 9 m³ volume.
After that four more blocks are placed on the lid. Means the pressure is increased from 4 atm to 8 atm (2 atm of lid, 2 atm of old blocks, 4 atm of new four blocks).
So, Data generated is,
P₁ = 4 atm
V₁ = 9 m³
P₂ = 8 atm
V₂ = ?
According to Boyle's Law,
P₁ V₁ = P₂ V₂
Solving for V₂,
V₂ = P₁ V₁ / P₂
Putting values,
V₂ = (4 atm × 9 m³) ÷ 8 atm
V₂ = 4.5 m³
Answer:
shear walls, cross braces, diaphragms, and moment-resisting frames are central to reinforcing a building. Shear walls are a useful building technology that helps to transfer earthquake forces. Made of panels, these walls help a building keep its shape during movement.
Explanation:
