A 14.1g sample of NaOH is dissolved in 200.0g of water in a coffee-cup colorimeter. The temperature increases from 20.0C to —-. Specific heat of liquid water is 4.18 J/g-K and deltaH for the dissolution of sodium hydroxide in water is 44.4kj/mol.

The temperature finally increased from 20 °C to 38.7 °C

Explanation:

This a problem about calorimetry. Formula to solve it is:

Q = m . C . ΔT

Where ΔT is Final T° - Initial T°

m is the mass

and C, specific heat.

In this situation we are dissolving NaOH where 1 mol requires 44.4 kJ of heat. As we do not have 1 mol, we need to determine the heat that is released.

We convert the mass to moles

14.1 g . 1 mol / 40g = 0.3525 mol

We determine the heat

0.3525 mol . 44400 J/mol = 15651 Joules of heat.

Now we can replace data in the calorimetry formula:

15651 J = 200 g . 4.18 J/g°C (Final T° - 20°C)

15651 J / (200 g . 4.18 J/g°C) = Final T° - 20°C

18.7°C + 20°C = Final T° → 38.7°C

assuming that your periodic table has eighteen columns, you should highlight   the four elements in the third column from the left of the table.

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the have energy higher than those in the orbital while lower than those of the orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the orbital is therefore filled right after orbitals and before orbitals.  

potassium has electron configuration and calcium . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the and should be highlighted as well.

4d^55s^1 ( third choice)