In: Chemistry
In: Chemistry
An atom of an element weighs 5.88 × 10-23 g. What is the atomic mass of this element in atomic mass units?
In: Chemistry
In: Chemistry
1. When chromium metal is added to nitric acid, the following reaction takes place Cr (s) + 6 HNO₃ (aq) → Cr(NO₃)₃ (aq) + 3 H₂O (l) + 3 NO₂ (g) Calculate the volume of NO₂ gas collected over water at 40.0 °C when 35.1 g of chromium is added to excess nitric acid if the total pressure is 675 torr. The vapor pressure of water at 40.0 °C is 55.3 torr.
and
2. How many grams of Al were reacted with excess HCl if 6.28 L of hydrogen gas were collected at STP in the following reaction? 2 Al (s) + 6 HCl (aq) → 2 AlCl₃ (aq) + 3 H₂ (g)
In: Chemistry
1.
An aqueous solution of calcium hydroxide is
standardized by titration with a 0.171 M solution
of hydroiodic acid.
If 27.0 mL of base are required to neutralize
10.6 mL of the acid, what is the molarity of the
calcium hydroxide solution?
_______M calcium hydroxide
An aqueous solution of hydrobromic acid is
standardized by titration with a 0.162 M solution
of calcium hydroxide.
If 23.9 mL of base are required to neutralize
27.6 mL of the acid, what is the molarity of the
hydrobromic acid solution?
_______M hydrobromic acid
2.
A 12.2 g sample of an aqueous solution of
hydroiodic acid contains an unknown amount of the
acid.
If 24.1 mL of 0.305 M
barium hydroxide are required to neutralize the
hydroiodic acid, what is the percent by mass of
hydroiodic acid in the mixture?
______% by mass
A 11.1 g sample of an aqueous solution of
hydrobromic acid contains an unknown amount of the
acid.
If 22.4 mL of 0.467 M
barium hydroxide are required to neutralize the
hydrobromic acid, what is the percent by mass of
hydrobromic acid in the mixture?
______% by mass
In: Chemistry
The human body contains 0.20% natural potassium. K-40 represents 0.0117% of naturally occurring potassium. 1. What is the radioactivity due to K-40 for a person weighing 70 kg? 2. What is the radioactivity due to K-40 for all people on Erath?
In: Chemistry
by comparing the instrumental design of a spectrophotometer and the spectrofluorometer, why does the emission spectrum of the blank have well defined peaks while the absorption spectrum is nearly flat?
(hint how do you define absorbance)
In: Chemistry
What are some medical or commercial applications of gases, and how are gas laws a part of those applications? Post a thorough initial response to the discussion question (at least 7-10 sentences, or approximately 150-200 words).
In: Chemistry
What must be the molarity of an aqueous solution of NH3 if it is 4.3 % ionized? Express your answer using two significant figures.
In: Chemistry
A student makes a solution in the laboratory by dissolving 53.5 g of NH4Cl in enough water to make 375 mL of solution, with a density of 1.05 g/mL
a. Calculate the Molarity of the
solution
b. Calculate the % mass of the NH4Cl in the
solution.
c. Calculate the mole fraction of NH4Cl in the
solution
d. Calculate the molality of NH4Cl in the solution
**Please show all work
In: Chemistry
What volume of O2 at 836 mmHg and 31 ∘C is required to synthesize 12.5 mol of NO?
Additional info: The industrial production of nitric acid (HNO3) is a multistep process. The first step is the oxidation of ammonia (NH3) over a catalyst with excess oxygen (O2) to produce nitrogen monoxide (NO)gas as shown by the unbalanced equation given here:
?NH3(g)+?O2(g)→?NO(g)+?H2O(g)
In: Chemistry
A fixed quantity of gas at 21 ∘C exhibits a pressure of 758 torr and occupies a volume of 5.42 L .
A) Calculate the volume the gas will occupy if the pressure is increased to 1.89 atm while the temperature is held constant.
B) Calculate the volume the gas will occupy if the temperature is increased to 185 ∘C while the pressure is held constant.
In: Chemistry
Part A Table of C-13 NMR data for 1-phenylcyclohexanol using the following headings for each compound (carbon types: CH, CH2, CH3, CH-OH, etc) Chemical Shift (ppm) Carbon Type
Part B Table of C-13 NMR data for 1-phenylcyclohexene using the following headings for each compound (carbon types: CH, CH2, CH3, CH-OH, etc):
Chemical Shift (ppm) Carbon Type
Give detailed explanation of the chemical Shift only and show the carbon labeled.
In: Chemistry
What are the theoretical bond energies and theoretical enthalpies for benzoic acid and sucrose?
In: Chemistry