An element's atomic number is 31. How many electrons would an atom of this element have?

A pump having the characteristics given in Fig. 14.10 pumps water at 20°C from a reservoir at an elevation of 366 m to a reservoir at an elevation of 450 m through a 36 cm steel pipe. If the pipe is 610 m long, what will be the discharge through the pipe?

Fig. 14.10Performance curves for a typical centrifugal pump; D = 37.1 cm

QUESTION 4 Before determining the ?soltnH of the salts in part B of Experiment 4 it's necessary to calibrate the calorimeter to effective heat capacity of the calorimeter. In order to do this, the neutralisation of hydrochloric acid and sodium hydroxide is used, where the ?H for the reaction is known, along with the specific heat and density of sodium chloride, the product of the reaction. By following the example on page 4-4 of the manual and the steps laid out in the table below determine Ccalorimeter in J K-1. The information that you need is shown in the table below. Value Enthalpy change for one mole ( \Delta H ?H) -58.3 kJ mol-1

Density 1 M NaCl (?) 1.037 g mL-1

Specific heat of 1 M NaCl solution ( C C) 3.90 g-1 K-1

Molarity of sodium hydroxide(aq) and hydrochloric acid(aq) used ( c c) 2 mol L-1

Volume of each of sodium hydroxide(aq) and hydrochloric acid(aq) used ( V V) 50 mL

Average neutralisation temperature rise ( \Delta T ?T) 11.2 °C

Calculation

Moles of H2O produced n (mol) = c (mol L ?1 ) ×V (L)

Enthalpy change for the reaction ? r H (kJ) =n (mol) ×?H (kJ mol ?1 )

Enthalpy change for the corresponding temperature change ? t H (kJ) =?? r H (kJ)

Mass of solution m (g) =V (mL) ×? (g mL ?1 )

Heat capacity of the solution C solution (J K ?1 ) =m (g) ×C (J g ?1 K ?1 )

The heat capacity of the calorimeter ( C calorimeter)

Calculate the pH and the equilibrium concentration of Se^2- in a 8.75×10^-2 M hydroselenic acid solution, H₂Se (aq).

For H₂Se, K_a1 = 1.3×10^-4 and K_a2 = 1.0×10^-11

Calculate the pH and the equilibrium concentrations of HS- and S2- in a 0.0425 M hydrosulfuric acid solution, H2S (aq).

For H2S, Ka1 = 1.0×10-7 and Ka2 = 1.0×10-19

Nicotine is to be extracted with kerosene from a water solution containing 1% nicotine. Water and kerosene are essentially immiscible. The equilibrium of a solute between immiscible solvents is expressed by the distribution coefficient, K, which is the ratio of the solute concentration in the two phases and for the distribution of nicotine between kerosene and water K = 0.9. Calculate the percent extraction of nicotine if 100 kg of feed solution is extracted once with 150 kg solvent.

A) If [M(H20)6]^2+ is red, which of the following complex ions could be yellow in solution?

1) [M(H2O)2Cl4]^2- 2) [M(H2O)4(SCN)2]

B)Which of the following complexes could have the orbital diagram below? (2 unpaired arrows on top row, 1 paired and 2 unpaired on bottom row.)

1) [CoI6]3- 2) [Ni(OH)4]^2- 3) [Fe(CO]6] ^3+

A gas obeys the following equation of state: P(v-b)=RT, where b is constant and has a value of 0.2 m³/Kmole. The heat capacity for the gas can be assumed constant at 40 Kj/Kmol oK.

(a)Calculate change in h and s for State 1(10 bar, 300 K) to State 2( 20 bar, 400 K).

(b) Show Cp is independent of pressure

In a pipe heat exchanger, crude oil on 30 ℃ is used to cool the heavy oil from 180℃ to 120℃.Mass flow of heavy oil is Wh=104kg / h，and crude oil respectively Wc=1.3×104kg/h. Specific heat, respectively is Cph=2.2 kJ/(kg•℃), Cpc=1.9 kJ/(kg•℃). Overall heat transfer coefficient K=120W/(m2•K). Try to calculate the required heat transfer area for parallel flow and countercurrent flow.

Make a list of instructions needed to be able t o extract mineral resources in a person's property.

Air (280 K and atmospheric pressure) enters a 3-m-long rectangular duct (0.15 m by 0.075 m) whose surface temperature is at 400 K. Air mass flow rate is 0.10 kg/s. Find the heat transfer and the outlet temperature. Use the Sieder-Tate equation to solve for the heat transfer coefficient.

A 2.00 mole sample of a perfect gas is heated from 41.2L and 255K to 42.2 L and 317K against a constant external pressure of 1.00 bar. What is delta H, delta U, q, and w for this process? (initial ---> intermediate---> final state). Intermediate state is V=41.2L, T=317K

Hint: first calculate delta h, delta u, q, and w for each arm. (Initial to intermediate being one arm, then intermediate to final being second arm)

Assume that Cp,m=3.5R and Cp,m-Cv,m=R

Water, hydrogen sulfide and selenium hydride are three similar molecules, but only one is the solvent of life. With reference to their chemical structure and the associated intermolecular forces, describe the molecular basis for some of the analous properties of liquid water and explain the significance of this with reference to H bonding, Coulumbic and Hydrophobic interaction IN BIOMOLECULES??

Hey guys if anyone can help, I would appreciate. I actually figure H bonding but Coulumbic and Hydrophobic i am having a lot of trouble.

1. Fundamentals of Heat Transfer:

2. Use of steam table:

3. team table are generally used

4. Heating value of hydrocarbons.

A wet solid is dried from 40% to 10% moisture under constant drying conditions in 5 hours. If
the equilibrium moisture content is 0.0416 kg moisture/kg dry solid and the critical moisture
content is 14%, how long will it take to dry from 40% to 5% moisture under the same conditions.
All percentages other than equilibrium moisture content are on wet basis. Assume linear relation
between rate of drying and moisture content during falling rate period.