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3 years ago

Why is using only clean glassware important?

2 answers:

6 0

Good laboratory technique demands clean glassware because the most carefully executed piece of work may give an erroneous result if dirty glassware is used. In all instances, glassware must be physically and chemically clean and in many cases, it must be bacteriologic-ally clean or sterile.

Lady_Fox [76]3 years ago

4 0

Keeping glassware physically neat and clean, free of grease, and bacteria is therefore of the utmost importance

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Pls help asap!!!!

AVprozaik [17]

Answer: The pressure of the He is 2.97 atm

Explanation:

According to Dalton's law, the total pressure is the sum of individual pressures.

$p_{total}=p_{N_2}+p_{O_2}+p_{He}.$

Given : $p_{total}$ =total pressure of gases = 6.50 atm

$p_{N_2}$ = partial pressure of Nitrogen = 1.23 atm

$p_{O_2}$ = partial pressure of oxygen = 2.3 atm

$p_{He}$ = partial pressure of Helium = ?

putting in the values we get:

$6.50atm=1.23atm+2.3atm+p_{He}$

$p_{He}=2.97atm$

The pressure of the He is 2.97 atm

3 0

3 years ago

Use tabulated standard electrode potentials to calculate the standard cell potential for the following reaction occurring in an

SVETLANKA909090 [29]

Answer : The standard cell potential of the reaction is, -1.46 V

Explanation :

The given balanced cell reaction is,

$3Pb^{2+}(aq)+2Cr(s)\rightarrow 2Cr^{3+}(aq)+3Pb(s)$

Here, chromium (Cr) undergoes oxidation by loss of electrons and act as an anode. Lead (Pb) undergoes reduction by gain of electrons and thus act as cathode.

The standard values of cell potentials are:

Standard reduction potential of lead $E^0_{[Pb^{2+}/Pb]}=-0.13V$

Standard reduction potential of chromium $E^0_{[Cr^{3+}/Cr]}=1.33V$

Now we have to calculate the standard cell potential for the following reaction.

$E^0=E^0_{cathode}-E^0_{anode}$

$E^0=E^0_{[Pb^{2+}/Pb]}-E^0_{[Cr^{3+}/Cr]}$

$E^0=(-0.13V)-1.33V=-1.46V$

Therefore, the standard cell potential of the reaction is, -1.46 V

6 0

4 years ago

Why is DNA a useful evolutionary clock?

hjlf

DNA is an evolutionary clock that's extremely useful in our lives because it mutates. The mutations that occur in our DNA causes the organisms to diverge evolutionarily from one another, providing us our natural clock in the timeline of evolution.

5 0

3 years ago

Read 2 more answers

What does acetic anhydride form when it reacts with water?

Stels [109]

What does acetic anhydride form when it reacts with water?

When acetic anhydride reacts with water it forms acetic acid. In other words, The hydrolysis of acetic anhydride in presence of water forms acetic acid.

*Note that:- It is an exothermic reaction.

7 0

3 years ago

Read 2 more answers

What do you notice about the distance between the terrestrial planets compared with the spacing between the gas giants

LekaFEV [45]

Answer:

The spacing between the terrestrial planets is less than that between the gas planets.

Explanation:

Since the terrestrial planets which are Mercury, Venus, Earth and Mars have a distance of 0.4 AU, 0.7 A.U, 1.0 AU and 1.5 A.U respectively from while the gas planets which are Jupiter, Saturn, Uranus and Neptune have a distance of 5.2 AU, 9.6 AU, 19.6 AU and 30 AU respectively from the sun, we can see that the spacing between the terrestrial planets is much smaller than the spacing between the gas planets.

For example, the spacing between Mercury and Venus is 0.7 AU - 0.4 AU = 0.3 AU while that between Earth and Venus is 1.0 AU - 0.7 AU = 0.3 AU.

Also, the spacing between Earth and Mars is 1.5 AU - 1.0 AU = 0.5 AU.

Also too, the spacing between the gas planets is shown below the spacing between Jupiter and Saturn is 9.6 AU - 5.2 AU = 4.4 AU while that between Uranus and Saturn is 19.6 AU - 9.6 AU = 10.0 AU.

Also, the spacing between Neptune and Uranus is 30 AU - 19.6 AU = 10.4 AU.

Thus, we can see that the spacing between the terrestrial planets is less than that between the gas planets.

Note that AU means astronomical unit and 1 AU is the distance between the Earth and the Sun. 1 AU = 1.50 × 10⁸ km

8 0

3 years ago