All categories

3 years ago

An atom of any element must contain

2 answers:

5 0

An atom (which by definition is neutral) should have (2) an equal number of protons and electrons.
If the number of protons and electrons are not equal, it becomes an ion.The number of protons and neutrons can vary widely depending on what the substance is and depending on the isotopes.

svetlana [45]3 years ago

4 0

An atom of any element must contain "<span>(2) an equal number of protons and electrons" but it should be noted that atoms can borrow electrons from one another. </span>

You might be interested in

All of the substances on the periodic table are classified as elements except

zzz [600]

Answer: all elements in the periodic table is classified as elements

Explanation:

The structure of the table shows periodic trends. The seven rows of the table, called periods, generally have metals on the left and nonmetals on the right. The columns, called groups, contain elements with similar chemical behaviours. Six groups have accepted names as well as assigned numbers: for example, group 17 elements are the halogens; and group 18 are the noble gases

6 0

3 years ago

Explain why the molar ratio is needed to determine the theoretical mass ratios.

choli [55]

Answer:

The overview of the subject is outlined underneath in the summary tab.

Explanation:

The molar ratio seems to be essentially a balanced chemical equilibrium coefficient that implies or serves as a conversion factor for the product-related reactants.
This ratio just says the reactant proportion which reacts, but not the exact quantity of the reacting product. Consequently, the molar ratio should only be used to provide theoretical instead of just a definite mass ratio.

3 0

2 years ago

A geologist finds a section of rock that shows was ripple marks. What does it he pr send me or a ripple marks say about the area

n200080 [17]

A beacuse the rock starts to tear away from the water which will then create ripple marks

3 0

3 years ago

Instead of using ratios for back titrations we can also use molarities, if our solutions are standardized. A 0.196 g sample of a

kvv77 [185]

Answer:

The mass percent of Al(OH)₃ is 15.3%

Explanation:

The reaction is:

Al(OH)₃ + 3HCl = AlCl₃ + 3H₂O

The excess acid is neutralized with a solution of sodium hidroxide, in the reaction:

NaOH + HCl = NaCl + H₂O

The total moles of HCl is:

$n_{HCl,total} =M_{HCl} *V_{HCl} =0.111*0.025=2.78x10^{-3} moles$

From the second titration, the moles of excess of HCl is:

$n_{HCl,excess} =n_{NaOH} =M_{NaOH} *V_{NaOH} =0.132*0.01105=1.46x10^{-3} moles$

The difference between the total and excess of HCl, it can be know the moles that reacts with the aluminum hydroxide, is:

$n_{HCl,reacts} =n_{HCl,total}-n_{HCl,excess} =2.78x10^{-3} moles-1.46x10^{-3} moles=1.32x10^{-3} moles$

The ratio between HCl and Al(OH)₃ is 3:1. The MW for aluminum hydroxide is 78 g/mol, thus:

$m_{Al(OH)3} =1.32x10^{-3} molesHCl*\frac{1molAl(OH)3}{3molesHCl} *\frac{78gAl(OH)3}{1molAl(OH)3} =0.03g$

The percentage of Al(OH)₃ is:

$Percentage-Al(OH)3=\frac{m_{Al(OH)3} }{m_{antiacid} } *100=\frac{0.03}{0.196} =15.3$ %

3 0

3 years ago

student has calibrated his/her calorimeter and finds the heat capacity to be 14.2 J/°C. S/he then determines the molar heat capa

nika2105 [10]

Answer:

24.03 J/mol.ºC

Explanation:

For a calorimeter, the heat lost must be equal to the heat gained from water plus the heat gained from calorimeter, which has the same initial temperature as the water.

-Qal = Qw + Qc (minus signal represents that the heat is lost)

-mal*Cal*ΔTal = mw*Cw*ΔTw + Cc*ΔTc

Where m is the mass, C is the specific heat, ΔT is the temperature variation, al is from aluminum. w from water and c from the calorimeter. Cw = 4.186 J/gºC

-25.5*Cal*(22.7 - 100) = 99.0*4.186*(22.7 - 18.6) + 14.2*(22.7 - 18.6)

1971.15Cal = 1699.10 + 58.22

1971.15Cal = 1757.32

Cal = 0.89 J/g.ºC

The molar mass of Al is 27 g/mol

Cal = 0.89 J/g.ºC * 27 g/mol

Cal = 24.03 J/mol.ºC

6 0

3 years ago