Answer: The friction force.
Justification:
Since the box is sliding over the table, the normal force equals the weight of the object (and any other vertical force that is applied on the box).
So, the normal force and weight (along with any other vertical component of a force applied on the box) must be 10 N and 10 N.
The other two forces: 14 N and 7 N are the forces in the plane of the table and should be opposite in a same line. The 14 N force is the responsible of the motion and the 7N force is opposing the 14 N force, so the 7N force has to be the friction force. Of course, 14N - 7N > 0 which is why the box is moving.
Answer:
is the mole fraction of potassium dichromate.
Explanation:
Mass of potassium dichromate = 24.42 g
Moles of potassium dichromate =
Mass of water = 240.0 g
Moles of water =
Mole fraction is calculated by:


is the mole fraction of potassium dichromate.
Double displacement reactions are when the cations and anions of 2 compounds are exchanged. Cation of one reactant will form a new product with the anion of the other reactant and vice versa.
MgCl₂ --> Mg²⁺ + 2Cl⁻
Na₂CO₃ --> 2Na⁺ + CO₃²⁻
the cations and anions are exchanged therefore double displacement reaction is as follows;
MgCl₂(aq) + Na₂CO₃(aq) --> MgCO₃(s) + 2NaCl(aq)
Answer:
The pressure of H₂(g) = 741 torr
Explanation:
Given that:
The atmospheric pressure measured in the lab = 765 torr
The vapor pressure of water = 24 torr
By applying Dalton's Law of Partial Pressure :

Making The Pressure inside the tube due to the H₂(g) the subject of the formula :
we have:

= (765 -24) torr
= 741 torr
Therefore; the pressure of H₂(g) = 741 torr
Answer:
-1.78 V
Explanation:
There are several rules required to calculate the cell potential:
- given standard cell potential, we may reverse the equation: the products of a given reaction become our reactants, while reactants become our products in the reversed equation. For a reversed equation, we change the sign of the cell potential to the opposite sign;
- if we multiply the whole equation by some number, this doesn't influence the cell potential value. It only produces a different expression in the equilibrium constant.
That said, notice that the initial reaction with respect to the final reaction is:
- reversed: chromium(III) cation and chloride anion become our reactants as opposed to the products in the initial reaction, so we change the sign of the cell potential to a negative value of -1.78 V;
- each coefficient is multiplied by a fraction of
. It doesn't influence the value of the cell potential.
Thus, we have a cell of E = -1.78 V.