Carbonic acid (H2CO3) is a weak diprotic acid with Ka1=4.43�10?7 and Ka2=4.73�10?11. When sodium bicarbonate (NaHCO3) is titrated with hydrochloric acid (HCl), it acts as a weak base according to the equation

NaHCO3(aq)+HCl(aq)?H2CO3(aq)+NaCl(aq)

1)What volume of 0.180M HCl is required for the complete neutralization of 1.50g of NaHCO3 (sodium bicarbonate)?

2)What volume of 0.120M HCl is required for the complete neutralization of 1.10g of Na2CO3 (sodium carbonate)?

3)A sample of NaOH (sodium hydroxide) contains a small amount of Na2CO3 (sodium carbonate). For titration to the phenolphthalein endpoint, 0.160g of this sample requires 23.98 mL of 0.100 M HCl. An additional 0.700 mL of 0.100 M HCl is required to reach the methyl orange endpoint. What is the percentage of Na2CO3 by mass in the sample?

1.

a) You have the following mixture by mass:

10% H+
6% He+
50% C3+
20% O2+
5% Fe4+
4% N2+
5% Mg+

Calculate the mean molecular weight, in units of mH (mass of hydrogen).

b) You are designing a mixture of neutral gas for a new rocket. For the reaction to take place, you need 10%
of oxygen by mass. Because of the payload restriction, the mean molecular weight of the gas must be
equal to 4 mH (mass hydrogen). Because of budget restriction, you are only allowed to mix the oxygen with 2 other
monoatomic gasses. Solve this problem, and provide a verification that your calculation is right.

An ideal gas mixture contains 220 mg N2 and 110 mg of O2. If the partial pressure of O2 at 27 oC is 19.8 kPa determine

(a) The total pressure
(b) The molar volume of the mixture
(c) The collision frequency, (i) zN2-O2 (ii) zO2-N2
(d) The mean free path of both gases
(e) The collision density (i) ZN2-O2 (ii) ZO2-N2
Given, the collision diameters of N2 and O2 are 3.75 and 3.61 Å, respectively.

1. A chemistry student five possible Lewis structures for the cyanate ion.

1. Give a reason why structures (4) and (5) are wrong. (2)

2. Calculate the formal charge of each individual atom and determine which structure is the preferred one. (11)

Structure 1

Structure 2

Structure 3

            _____________________________________ is the most stable structure.

            _____________________________________ is the least stable structure.

1a. Arrange BaS,  GaP,  CaO,  RbCl in order of decreasing lattice energy. (2)

1b. Arrange KBr,  InAs,  LiCl,  SrSe,  ZnS in order of increasing lattice energy. (

When plotting a calibration curve to use for ion chromatography, would it be better to use peak area or peak height vs concentration ? Is the R-squared value a good basis for which to choose?

17) A 8.10 L container holds a mixture of two gases at 21 °C. The partial pressures of gas A and gas B, respectively, are 0.369 atm and 0.755 atm. If 0.120 mol of a third gas is added with no change in volume or temperature, what will the total pressure become?

18) A gas mixture is made by combining 8.0 g each of Ar, Ne, and an unknown diatomic gas. At STP, the mixture occupies a volume of 18.97 L. What is the molar mass of the unknown gas?

24) At a certain temperature and pressure, 1 L of CO2 gas weighs 2.05 g. What is the mass of 1 L of CO gas at the same temperature and pressure?

Baking powder is a mixture of sodium bicarbonate and an acid, often cream of tartar (made of tartaric acid, H2C4H5O6). These two components react when they are dissolved in water. A partial balanced equation for this reaction is shown below. Fill in the blank spaces with the appropriate compounds and/or coefficients: __NaHCO3(aq)+__H2C4H5O6(aq)-->______+_______+Na2C4H5O6(aq). A particular formulation of baking powder contains 2.13 g sodium bicarbonate and 4.67 g tartaric acid. How many millileters of gas will be released at STP?(R constant is 0.082 057 366 L atm/mol K)(If possible please try and help me with the net ionic equation too)

Answer the questions on Hess's Law listed below. Please note that you must include units throughout all of your calculations and provide your answer in scientific notation to the correct number of significant digits.

Click on the red flags to the left to review content on scientific notation and significant digits.

Question 1

Iron is made from a reaction of iron oxide with carbon monoxide in the following reaction:

Fe₂O_3(s) + 3 CO_(g) → 2 Fe_(s) + 3 CO_2(g)

Using Hess' Law, calculate the enthalpy of reaction given:

Question 2

Use Hess' Law to calculate enthalpy of reaction for the following equation:

2 N_2(g) + 5 O_2(g) → 2 N₂O_5(g)

Given:

Question 3

Using standard enthalpies of formation, determine the ΔH_reaction for the following equations:

2 CH₃OH_(l) + 3 O_2(g) → 2 CO_2(g) + 4 H₂O_(g)

Give Lewis dot structures and shapes for the following:

a.VOCl₃

b.PCl₃

c.SOF₄

d.SO₃

e.ICl₃

f.SF₆

g.IF₇

h.XeO₂F₄

i.CF₂Cl₂

j.P₄O₆

_{explain properly with explanation of hybridisation explain hybridisation of each part properly}

Calculate the equilibrium composition for the reaction Cgraphite + H2O(g) _<->CO(g) + H2(g) at T = 298 K, 500 K, 1000 K, and 2000 K and a pressure of 1 bar. For the initial number of moles, use 1 mole of graphite, 3 moles of H2O(g), and no CO or H2.

Ca(OH)2 dissolves exothermically in water and the molar solubility of Ca(OH)2 decreased as the temperature increases. What are the signs of Delta H and Delta S for dissolving Ca(OH)2?

Among the following pairs of solvents, which layer would be on top? Or would they be miscible? Explain.

Water and Cyclohexene

Water and Hexane

Help PLease?

Can someone explain and sketch what a distillation would look like "in a slow stream of nitrogen introduced through a capillary leak"?

Or how I could do that in a student lab type setting? We received a synthesis for a product which has the procedure, but we are supposed to write it up where we could do it in the lab.

Gaseous butane

CH3CH22CH3

reacts with gaseous oxygen gas

O2

to produce gaseous carbon dioxide

CO2

and gaseous water

H2O

. If

36.4g

of water is produced from the reaction of

49.99g

of butane and

339.9g

of oxygen gas, calculate the percent yield of water.

Round your answer to

3

significant figures.