Answer:
Calcium is a Group 2 metal. Fluorine is a Group 17 gas. Towards the right of the Periodic table, ELEMENTS tend to get smaller as the increased nuclear charge exerts a greater attractive force on the valence electrons. The small fluorine atom tends to attract electrons, and is energetically most stable when it forms the F
− ion. On the other hand, calcium is a large Group 2 metal. It has 2 valence electrons, which are in the valence (the outermost) shell, and nuclear charge is somewhat diminished for these electrons. Calcium tends to be oxidized (to lose electrons) to form C a 2
+ ions. So if calcium and fluorine want to make music together (or at least form a chemical bond), then a formula of (C a F 2) is entirely reasonable (why? because this combination is electrically neutral!). And in fact in nature the mineral fluorite (
C a F
2
) is very widespread.
Answer:
The shear stress is 2.16 Pa
Explanation:
Newton's law of viscosity can be expressed as follows;
Where:
τ = Shear stress in the fluid
Given that the diameter of the wire = 5 cm
The velocity of the wire = 18 cm/s
The diameter of the pipe = 10 cm
The fluid viscosity, μ = 3.0 cp = 1×10⁻³· Pa·s
The change in velocity from the surface of the wire to the internal surface of the pipe = dv = 18 cm/s
The change in the y (perpendicular) direction of motion of the fluid from the surface of the wire to the interior surface of the tube = dy = 10/2 - 5/2 = 2.5 cm
By putting in the values, we have;
The shear stress = 2.16 Pa
Answer:
The correct statements are (II) and (III).
Explanation:
Any change in the equilibrium is studied on the basis of Le-Chatelier's principle.
This principle states that if there is any change in the variables of the reaction, the equilibrium will shift in the direction to minimize the effect.
For the given equation:
This is a type of exothermic reaction because heat is released in the reaction.
On increasing the temperature
If the temperature is increased, so according to the Le-Chatlier's principle , the equilibrium will shift in the direction where decrease in temperature occurs. As, this is an exothermic reaction, forward reaction will increase the temperature. Hence, the equilibrium will shift in the left direction.
And by moving to left side amount of ammonia will decrease accompanied by the change in the value of an equilibrium constant.
The heat will flow from Cu to Fe because Cu has higher temperature and has lower peak value .
Given ,
two aircraft rivets , one iron and the other copper , are placed in a calorimeter .
the initial temp of the calorimeter is 20 degC .
mass of iron = 30 g
initial temp of iron = 0 degC
Mass of copper = 20 g
initial temp of copper = 100 degC
Here copper has higher temp ,thus heat flow from Cu to Fe .
<h3>
What is heat flow ?</h3>
Heat flow is the movement of heat from higher temperature to lower temperature .
<h3>What is calorimeter ?</h3>
It is an object used for measuring the heat flow , heat capacity of a chemical reaction as well as the physical changes .
Learn more about calorimeter here :
brainly.com/question/1407669
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Answer:
c. 0.200 M HCI(aq)
Explanation:
The titration of a base as NH3 with hydrochloric acid is:
NH3 + HCl → NH4Cl
<em>Where 1 mole of NH3 reacts per mole of HCl</em>
<em />
The recommended volume to read in a burette is between 60 and 80% of its capacity.
That is 60% 50.0mL = 30mL and 80% 50.0mL = 40mL must be spent.
A 6.00M HCl spend:
20mL * (0.3mol/L) * (1L/ 6.00M) = 1mL. This solution is not the ideal for the titration.
A 0.3M HCl spend:
20mL * (0.3mol/L) * (1L/ 0.3M) = 20mL. This solution is not the ideal for the titration.
A 0.200M HCl spend:
20mL * (0.3mol/L) * (1L/ 0.200M) = 30mL. This solution ideal for the titration.
A 0.100M HCl spend:
20mL * (0.3mol/L) * (1L/ 0.100M) = 60mL. This solution is not the ideal for the titration.
Right option is:
<h3>c. 0.200 M HCI(aq)</h3>
