A 0.274 M solution of sulfuric acid (H2SO4) is to be reacted with a 0.266 M solution of sodium hydroxide to make sodium sulfate and water. How many L of the H2SO4 solution will react with 0.867 L of the NaOH solution?

NaOH ---> (0.266 mol/L) (0.867 L) = 0.230622 mol

H2SO4 + 2NaOH ---> Na2SO4 + 2H2O

For every two NaOH used up, one H2SO4 reacts.

H2SO4 ---> 0.230622 mol / 2 = 0.115311 mol

(0.274 mol/L) (x) = 0.115311 mol

x = 0.421 L (to three sig figs)

When discussing acids and bases, a solution containing a large number of hydronium ions, by definition, is considered a(n)

A. Arrhenius acid.
B. Arrhenius base.
C. Brønsted-Lowry acid.
D. Brønsted-Lowry base.


A, The answer is Arrenhius acid because the definition of an Arrenhius acid is very specific and that is that the substance must donate H+ ions (H+ ions are typically interchangebly written with H30+ in aqueous solutions of water). The second closest answer would be Bronsted lowry acid but it is not correct because Bronsted lowry acids only donate protons and this definition is much more vague than the Arrenhius acid definition.

All of the following are classified as bases except

A. lye.
B. ammonia.
C. lime juice.
D. baking soda.


C, Lime juice tastes sour and acids typically have a sour taste. The rest of the choices are all definitely bases as ammonia is a very popular weak base in chemistry and baking soda is a very powerful base. 

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An acid's hydronium ion will donate its proton to a base's hydroxide ion, _________ both.

A. acidifying
B. alkalizing
C. neutralizing


C, Once an acid's H+ combines with a bases' OH-, the two ions form water (H2O) with a pH of neutral 7. Thus, this process is neutralization as both the acid and basic properties are now canceling each other out. Keep in mind though that this question is talking specifically about Arrenhius acid and bases so neutralization reactions can also occur with acids and bases other than H+ and OH-. 

When discussing acids and bases, any substance that accepts a proton, by definition, is considered a(n)

A. Arrhenius acid.
B. Arrhenius base.
C. Brønsted-Lowry acid.
D. Brønsted-Lowry base.


D, Bronsted Lowry base for sure because its definition is any substance that accepts a proton (or essentially a H+ ion). Bronsted Lowry acids donate protons to other substances and the other substances that accepts those protons become Bronsted Lowry bases. Arrenhius acids are substances that must donate H+ and Arrnehius bases, on the other hand, must donate OH- and so neither are correct for this question.

What is a property of a base?

What is a property of a base?
A. bitter taste
B. watery feel
C. unreactive
D. nonelectrolyte


1) A, Bases definitely have a bitter taste (not that I have tasted them before lol) while acids have a sour taste (like Coca-cola). I'm not sure why they taste the way they do but for sure this answer is not B,C or D because bases are definitely electrolytes (they dissolve in water) and they are not unreactive. Watery feel is quite a funny answer because I highly recommend you to not ever touch a base (they can burn you just as bad as an acid can if it has a really high pH or low pOH).

How do you dilute a solution that contains 50 g of sucrose dissolved in 1L of water?

If you have a solution that contains 50g of sucrose in 1L of water, you can simply dilute it by adding more water to it. This is because if you calculate the current molarity of this solution (convert 50g of sucrose to moles and then divide it over 1L to find the molarity) it will be about 0.146moles/liters. If you add more liters of water, you will notice that the denominator will become larger and hence, the total moles per liter will begin to decrease or dilute. 

Calculation of pH of solution using pKa?

20cm³ of 1mol per dm³ nitrous acid (pKa = 3.34) is added to 40 cm³ of 0.5 mol per dm³ sodium nitrate solution. What is the pH of the solution? Help please because I am unsure as to whether im supposed to calculate the pH using the number of moles or mol per dm³. And can you explain why mole or concentration is used.


It appears you a dealing with a buffer solution. However, the mixture is not that of a acid and its conjugate base. Perhaps you meant sodium nitrite (not nitrate). In that case 

pH = pKa + log[NO2-]/[HNO2]

[NO2-] = 0.040*0.5/0.060 M (there are 60 cc of solution after mixing)
[HNO2] = 0.020*1/0.060 M

Since the volumes after mixing are the same, you can use moles or concentration, but the formula is based on molar concentration.

[NO2-]/[HNO2] = 0.040*0.5 / 0.020*1 = 1.0; log1.0 = 0, so pH = pKa

Which is the least inert gas among them? He Ar Xe Ne Kr

The reactivity of the noble gases increases with increasing atomic number. Xenon has the largest atomic number in the given group.

Calculate the weight of lime(CaO) obtained by heating 200kg of 95% pure limestone(CaCO3)?

95% of 200 kg = 190 kg.
The molar mass of CaCO₃ is 100 g/mol, so 190 kg = (190,000 g)/(100 g/mol)
= 1900 mol.
CaCO₃ → CaO + CO₂, so 1900 mol of CO₂ are removed by heating. The molar mass of CO₂ is 44 g/mol, so 1900 mol = (1900 mol)(44 g/mol) = 83 600 g = 83.6 kg.
190 kg - 83.6 kg = 106.4 kg CaO.

If 0.30 mol of Zn are added to HCl containing 0.52 mol of HCl , how many moles of hydrogen are produced?

Zinc and HCl react according to the following reaction:

Zn(s) + 2 HCl(aq)-------->ZnCl2(aq) + H2(g)

You need 2 moles of HCl to neutralize 1 mole of Zn
So 0.52 moles of HCl produce 0.52/2= 0.26 moles of gas H2

Balance in acidic soln:Tin(II) is oxidized to tin(IV) with hydrogen peroxide, Sn2+(aq)+H2O2(aq)=H2O(l)+Sn4+?c

Tin (II) is oxidized to tin (IV) with hydrogen peroxide: Sn2+ (aq) + H2O2 (aq) -> H2O (l) + Sn 4+ (aq). Balance the equation in an acidic solution.


Sn2+ -----------> Sn4+ + 2e- oxidation

H2O2 + 2H+ + 2e- ---------> 2H2O reduction 

adding both equation, gives
Sn2+ + H2O2 + 2H+ ------------> 2 H2O + Sn4+

Which of the following particles when moving causes electricity?

a hydrogen atom
a proton
an electron --> Answer!!
a hydrogen ion

How do two negative charges interact when they are brought close together?

attract
no interaction
repel
ground


The answer is repel . Because only negative charges interact with positive charges.

Electric charge flows from higher_____to lower.

induction
circuit
voltage --> answer
power

0.5g of zinc powder was found to reduce an acidified solution of 25.50 cm^3 of 0.200 mol/dm^3 AO2^+ . What Is the final oxidation number of metal A . Options : A) 0. B) +1 C) +2. D) +3

0.5 g / 65.409 g/mol = 0.0076442 mol of Zn

Zn ---> Zn2+ + 2e-

0.0076442 mol times2 = 0.0152884 mol of electrons produced

MV = moles

(0.200 mol/L) (0.02550 L ) = 0.0051 mol of AO2^+

0.0152884 mol / 0.0051 mol = 2.998 = 3

In AO2^+, the oxidation number of A is +5. It was reduced by 3 oxidation numbers to +2.

Answer choice C

Balance the following

Cl2 + NaBr -> ?
CaCO3 -> ?
Zn + HCl -> ?
Ca(OH)2 -> ?
H3PO4 + KOH -> ?
AgNO3 + Ha -> ?
-------------------------------------------------------------------


Balanced equations have equal numbers of atoms on each side. The net charge also balances. The number of molecules does not have to be equal.

Cl2 + 2NaBr -> Br2 + 2 NaCl (REDOX : Bromine is reduced by Chlorine)

CaCO3 ->Ca(+2) + CO3(-2) (not very soluble, but these ions form)

Zn + 2HCl ->ZnCl2 + H2 (classic metal + acid = salt and gas)

Ca(OH)2 ->Ca(+2) + 2OH(-) (not very soluble, but these ions form)

(acid + base = salt and water)
H3PO4 + KOH ->KH2PO4 + H2O (Potassium dihydrogen phosphate formed)
H3PO4 + 2KOH ->K2HPO4 + 2H2O (Potassium hydrogen phosphate formed)
H3PO4 + 3KOH ->K3PO4 + 3H2O (Potassium phosphate formed)

AgNO3 + Ha ->Aga + HNO3 ("Ha" is some kind of acid)

You might want to include those silly subscripts like "(g)", "(s)" and "(aq)" which chemnistry teachers are so fond of. Working chemists never use them.

What is the half-life (in years) of 44-Ti if a 1.0 ng sample decays initially at a rate of 4.8x 10^3 disintegrations per second?

1 ng = 1*10^-9 g = 4.8*10^3 Bq 
1 g = 4.8*10^12 Bq 

the specific activity of an isotope is found by
A = ln(2)/T1/2 * N/M

with T1/2 = half life in seconds 
N = Avogadro's constant = 6.022*10^23 atoms/mol
M = molecular mass in g = 44

T1/2 = ln(2)*N/(A*M) 

T1/2 = ln(2)*6.022*10^23/(4.8*10^12*44) 
T = 1.976*10^9 s 

T = 1.976*10^9/(365*24*60^2) years 
= 62.65 years
(Wiki says 49 years though) 

Of the metals Au, Fe, Na and Cd which will not give up its electrons to silver (Ag) in a redox reaction?

Au

Fe

Na

Cd

-----------------

Au - because it is less reactive than Ag