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2 years ago

4. Define power and explain how to determine power.

1 answer:

5 0

The rate of doing work is called power of an object.
It is also defined as the work done by an object per unit time. Mathematically, its formula is given by :
, W is work done and t is time taken.
The SI unit of power is watts and its commercial unit is kWh.
1 watt = J/s or N-m/s.

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g You observed the formation of several precipitates in the Reactions in Solution lab exercise. Identify the precipitate in each

RUDIKE [14]

Answer:

For a: Lead iodide is a yellow precipitate.

For b: Barium sulfate is a white precipitate.

For c: Ferric hydroxide is a brown precipitate.

For d: Copper (II) hydroxide is a blue precipitate.

Explanation:

Precipitation reaction is defined as the reaction where a solid precipitate (solid substance) is formed at the end of the reaction. It is insoluble in water.

For the given options:

For (a):

The chemical reaction between KI and lead (II) nitrate follows:

$2KI(aq)+Pb(NO_3)_2(aq)\rightarrow PbI_2(s)+2KNO_3(aq)$

The iodide of lead is generally insoluble in water. Thus, lead iodide is a yellow precipitate.

For b:

The chemical reaction between barium chloride and sulfuric acid follows:

$BaCl_2(aq)+H_2SO_4(aq)\rightarrow BaSO_4(s)+2HCl(aq)$

The sulfate of barium is insoluble in water. Thus, barium sulfate is a white precipitate.

For c:

The chemical reaction between NaOH and ferric chloride follows:

$3NaOH(aq)+FeCl_3(aq)\rightarrow Fe(OH)_3(s)+3NaCl(aq)$

The hydroxide of iron is insoluble in water. Thus, ferric hydroxide is a brown precipitate.

For d:

The chemical reaction between NaOH and copper sulfate follows:

$CuSO_4+2NaOH\rightarrow Cu(OH)_2+Na_2SO_4$

The hydroxide of copper is insoluble in water. Thus, copper (II) hydroxide is a blue precipitate.

6 0

2 years ago

From the Henderson-Hasselbalch equation, explain how the ratio [Al/[HA] changes with changing pH

Kryger [21]

Answer:

The ratio [A-]/[HA] increase when the pH increase and the ratio decrease when the pH decrease.

Explanation:

Every weak acid or base is at equilibrium with its conjugate base or acid respectively when it is dissolved in water.

$HA + H_{2}O$ ⇄ $A^{-} + H_{3}O^{+}$

This equilibrium depends on the molecule and it acidic constant (Ka). The Henderson-Hasselbalch equation,

$pH = pKa + Log \frac{[A^{-}]}{[HA]}$

shows the dependency between the pH of the solution, the pKa and the concentration of the species. If the pH decreases the concentration of protons will increase and the ratio between A- and AH will decrease. Instead, if the pH increases the concentration of protons will decreases and the ratio between A- and AH will increase.

5 0

3 years ago

2.46 grams of Cu(NO3)2 would contain how many formula units

NikAS [45]

Answer:

it woul be 263

Explanation:

becaue it adds up like that

7 0

2 years ago

Only _____ live part of their lives like fish and the rest of their lives as land animals.

dedylja [7]

Answer:

amphibians

Explanation:

because frogs have to stay in water while tadpole then they come to land

6 0

2 years ago

Read 2 more answers

Mantle convection is a process of that creates circular currents in the asthenosphere. As a result, the plates slowly move.

LUCKY_DIMON [66]

Answer:

Rigid plates that move around Earth's surface is called tectonic plates. 

Explanation:

Lithosphere is rigid and relatively cold and is the outer surface of the planet. The convective motions of maintenance break the lithosphere into plates.

This place that a form can move in any direction, can move towards each other, can move away and push each other which is the reason for formation of mountains for shifting of continents for making of ocean basin.

8 0

3 years ago