Questions
Why metals do not fracture?

Why metals do not fracture?

In: Chemistry

The parameter g varies with temperature for molecular gases because of the varying contributions from molecular...

The parameter g varies with temperature for molecular gases because of the varying contributions from molecular vibrations. Determine g in the low-temperature and the high- temperature limits for (a) CO2 (g) and (b) H2O (g).

In: Chemistry

At 650 K, the reaction MgCO3(s)<->MgO(s)+CO2(g) has Kp=0.026. A 10.1L container at 650 K has 1.0g...

At 650 K, the reaction MgCO3(s)<->MgO(s)+CO2(g) has Kp=0.026. A 10.1L container at 650 K has 1.0g of MgO(s) and CO2 at P = 0.0260 atm. The container is then compressed to a volume of0.500L . Find the mass of MgCO3 that is formed.

In: Chemistry

What percentage reduction in carbon emissions do the following natural gas-fired CHP systems provide compared to...

What percentage reduction in carbon emissions do the following natural gas-fired CHP systems provide compared to the specified separately generated electricity and heat systems? For carbon emissions, assume natural gas emits 53 g CO2/MJ, and for average grid emissions assume 0.6 kg CO 2 /kWh. The joule equivalent of 1 kWh of electricity is 3.6 MJ.

a. CHP with 36% electrical efficiency and 40% thermal efficiency versus an 85%-efficient gas boiler for heat and the above average grid for electricity.

b. CHP with 50% electrical efficiency and 20% thermal efficiency versus a 33%-efficient, 1.0 kg CO 2 /kWh, coal-fired power plant for electricity and an 80%-efficient gas-fired boiler for heat.

In: Chemistry

If I want to make 12 g of XeO2 from the elements, how much Xe do...

If I want to make 12 g of XeO2 from the elements, how much Xe do I need, in grams

In: Chemistry

a) If 42.1 mL of 1.02 M sodium hydroxide, measured using a graduated cylinder, is placed...

a) If 42.1 mL of 1.02 M sodium hydroxide, measured using a graduated cylinder, is placed in a beaker filled with 300 mL of DI water, what is the concentration of the diluted NaOH solution?

b) Why does this calculation only provide an estimate of the NaOH concentration? In other words, why do we have to standardize the NaOH in this experiment to find its exact concentration? (Hint: think about the glassware

In: Chemistry

Is density by calculation more accurate than density by immersion, why or why not?

Is density by calculation more accurate than density by immersion, why or why not?

In: Chemistry

What is the equilibrium concentration of PO4 in a 0.511 M solution of H3PO4 (Ka1 =...

What is the equilibrium concentration of PO4 in a 0.511 M solution of H3PO4 (Ka1 = 7.5E-3, ka2= 6.2E-8, ka3= 4.8E-13) I troes using the 5% rule but when i checked my work i was at 11%. I dont know how to solve this if i cant use the 5% rule. Help please.

In: Chemistry

Ethane (CH3CH3) and Fluoromethane (CH3F) have the same number of electrons and are essentially the same...

  1. Ethane (CH3CH3) and Fluoromethane (CH3F) have the same number of electrons and are essentially the same size. However, ethane has a boiling point of 184.5C and fluoromethane has a boiling point of 194.7C. Which answer best explains this 10 degree difference in boiling point in terms of the van der Waals forces present.

In: Chemistry

To convert from a given quantity of one reactant or product to the quantity of another...

To convert from a given quantity of one reactant or product to the quantity of another reactant or product:

First, convert the given quantity to moles. Use molar masses to convert masses to moles, and use Avogadro's number (6.02×1023 particles per mole) to convert number of particles to moles.

Next, convert moles of the given reactant or product to moles of the desired reactant or product using the coefficients of the balanced chemical equation. For example, in the chemical equation

2H2+O2→2H2O

the coefficients tell us that 2 mol of H2 reacts with 1 mol of O2 to produce 2 mol of H2O.

Finally, convert moles of the desired reactant or product back to the desired units. Again, use molar masses to convert from moles to masses, and use Avogadro's number to convert from moles to number of particles.

part A. How many grams of NH3 can be produced from 3.19 mol of N2 and excess H2.

part B. How many grams of H2 are needed to produce 14.94 g of NH3?

part C. How many molecules (not moles) of NH3 are produced from 3.33×10−4 g of H2?

2. When methane (CH4) burns, it reacts with oxygen gas to produce carbon dioxide and water. The unbalanced equation for this reaction is

CH4(g)+O2(g)→CO2(g)+H2O(g)

This type of reaction is referred to as a complete combustion reaction.

Part a. What mass of carbon dioxide is produced from the complete combustion of 2.00×10−3 g of methane?

Part b. What mass of water is produced from the complete combustion of 2.00×10−3 g of methane?

Part c. What mass of oxygen is needed for the complete combustion of 2.00×10−3 g of methane?

3. Aluminum reacts with chlorine gas to form aluminum chloride via the following reaction:

2Al(s)+3Cl2(g)→2AlCl3(s)

Aluminum reacts with chlorine gas to form aluminum chloride via the following reaction:

2Al(s)+3Cl2(g)→2AlCl3(s)

Part a. What is the maximum mass of aluminum chloride that can be formed when reacting 31.0 g of aluminum with 36.0 g of chlorine?

Express your answer to three significant figures and include the appropriate units.

4.

Determine the balanced chemical equation for this reaction.

C8H18(g)+O2(g)→CO2(g)+H2O(g)

Enter the coefficients for each compound in order, separated by commas. For example, 1,2,3,4 would indicate one mole of C8H18, two moles of O2, three moles of CO2, and four moles of H2O.

5. 1.66 g H2 is allowed to react with 10.3 g N2, producing 1.62 g NH3.

Part A

What is the theoretical yield in grams for this reaction under the given conditions?

Express your answer to three significant figures and include the appropriate units.

You are given 31.0 g of aluminum and 36.0 g of chlorine gas.

Part B

What is the percent yield for this reaction under the given conditions?

Express your answer to three significant figures and include the appropriate units.

In: Chemistry

15- Propane gas flows into a combustion chamber at a rate 250 L/min at 2.0 atmand...

15- Propane gas flows into a combustion chamber at a rate 250 L/min at 2.0 atmand ambient temperature. Air is added to the chamber at 1.0 atm and the same temperature. The gases are ignited.

a) To get complete combustion of the propane to carbon dioxide and water three times as much oxygen as is stoichiometrically appropriate is required. Assuming air is 21% oxygen and 79% nitrogen, calculate the required flow rate of air?

b )Under the conditions in part a, the combustion is not complete and a mixture of carbon dioxide and carbon monoxide is produced. It is determined that 94.0% of the carbon in the exhaust gas is present as carbon dioxide. The remainder is carbon monoxide. Calculate the percent composition of the exhaust gas in terms of mole fraction of CO, CO2 , O2 , N2 , and H2O. Assume the propane is completely reacted and the nitrogen is totally unreacted.

Can you please explain part B? I got 476.190 mL/min for part A.

In: Chemistry

Why is there more than one definition of acid-base behavior? Which definition is the right one?

Why is there more than one definition of acid-base behavior? Which definition is the right one?

In: Chemistry

What is the pH of the buffer that results when 0.235 mol of NH3 and (2.46x10^-1)...

What is the pH of the buffer that results when 0.235 mol of NH3 and (2.46x10^-1) mol of NH4Cl are dissolved in water to a volume of 0.50 L? (Ka of NH4(+) = 5.6E-10)

In: Chemistry

8.0g of aluminum at 200?C and 21g of copper are dropped into 45cm3 of ethyl alcohol...

8.0g of aluminum at 200?C and 21g of copper are dropped into 45cm3 of ethyl alcohol at 15?C . The temperature quickly comes to 27?C.

What was the initial temperature of the copper?

In: Chemistry

Complete and balance the precipitation reactions. Include physical states in your equations. Click here for solubility...

Complete and balance the precipitation reactions. Include physical states in your equations. Click here for solubility rules.

A.) AgNO3(aq)+NaCl(aq)----->

B.) K3PO4(aq)+MgCl2(aq)----->

In: Chemistry