Complete Question
A voltaic cell utilizes the following reaction and operates at 298 K:
3Ce4+(aq)+Cr(s)→3Ce3+(aq)+Cr3+(aq).
What is the emf of this cell under standard conditions? Express your answer using three significant figures.
Answer:
The value is 
Explanation:
From the question we are told that
The ionic equation is

Now under standard conditions the reduction half reaction is

And the oxidation half reaction is

The emf of this cell under standard conditions is mathematically represented as

substituting values


I will assume here that the well is sufficiently short so that the time the sound takes to come from the bottom of the well to our ear is negligible.
Since the pebble moves by uniformly accelerated motion, the distance it covers is given by

where

is the gravitational acceleration

is the time the pebble takes to reach the bottom of the well
Therefore, the depth of the well is

and the correct answer is B.
Answer:
Kindly check the explanation section.
Explanation:
For the design we are asked for in this question/problem there is the need for us to calculate or determine the strength in fracture and that of the yield. Also, we need to calculate for the block shear strength.
From the question, we have that the factored load = 500kips. Also, note that the tension splice must not slip.
Also, the shear force are resisted by friction, that is to say shear resistance = 1.13 × Tb × Ns.
Assuming our db = 3/4 inches, then the slip critical resistance to shear service load = 18ksi(refer to AISC manual for the table).
If db = 7/8 inches, then the shear force resistance for n bolt = 10.2kips, n > 49.6.
The yielding strength = 0.9 × Aj × Fhb= 736 kips > 500
The fracture strength = .75 × Ah × Fhb = 309 kips.
The bearing strength of 7/8 inches bolt at the edge hole and other holes = 46 kips and 102 kips.
Explanation:
Solution,
Volume (v)=287 cm^3
Mass(m)=816 g
Density(d)=m/v
=816/287
=2.84
So, the density of the block of marbles is 2.84 g/cm^3.
I hope it helped U
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