# Posts by Jefferson

Total # Posts: 22

**Social studies please help**

Meme and Crazy Kid are correct... I assume hoppee has a different quiz, or is trying to give bad grades.

**Social studies please help**

Ok. I am taking the quiz, and I will see who is right.

**math**

Find the second derivative of y^2 = 4rp

**math**

The number that is IX more tham XC

**physics**

The weight of a solid in air is four times greater than the weight of solid in water. Find its weight of which solid in water if it has relative density is 64.

**physics**

a=~2.84 m/s^2

**Chemistry**

How many grams of solid product should form if 4.90 grams of sodium phosphate is mixed with 25 ml of .875M barium nitrate?

**Chemistry**

#6 If 10.0 grams of Aluminum carbonate(s) decomposes to produce aluminum oxide(s) and carbon dioxide(g), how many grams of CO2(g) are formed? If 5.00 grams is recovered experimentally what is the percent yield?

**Chemistry**

#5 Limiting Reactants How many grams of water will be produced in the complete combustion of 20.0 grams of Octane, C8H18(g) and 50.0 grams Oxygen gas?

**Chemistry**

#6. If 10.0g of Aluminum carbonate(s) decomposes to produce aluminum oxide(s) and carbon dioxide(g), how many grams of CO2(g) are formed? If 5.00g is recovered experimentally what is the % yield?

**Chemistry**

How many grams of water will be produced in the complete combustion of 20.0g of Octane, C8H18(g) and 50.0g Oxygen gas?

**Chemistry**

How many grams of water are produced when 10.0g of Butane, C4H10(g) completely combust with 2.50 moles of Oxygen gas?

**Chemistry**

A strip of zinc medal weighing 2.00 grams is placed in an aqueous solution containing 150.ml of .750M Tin(II) nitrate. Determine the grams of tin metal that will be precipitated.

**Chemistry**

Lead(II) carbonate decomposes to form Lead(II) oxide and carbon dioxide. If 5.oo grams of the reactant decomposes to produce 1.52 grams of Lead(II) oxide experimentally, what is the theoretical yield and percent yield.

**Chemistry**

NH3 is a weak base (Kb = 1.8 × 10–5) and so the salt NH4Cl acts as a weak acid. What is the pH of a solution that is 0.050 M in NH4Cl?

**Chemistry**

If the pH of a solution is 6, what are the hydrogen- and hydroxide-ion concentrations? The PH of a 0.1 M MCl (M+ is an unknown cation) was found to be 4.7. Write the net ionic equation for the hydrolysis of M+ and its corresponding equilibrium expression Kb. Calculate the ...

**Chemistry**

got it!! the answer is 0.6 and it was correct!! Thank you so so much!!

**Chemistry**

At equilibrium, the concentrations in this system were found to be [N2]=[O2]=0.100 M and [NO]=0.400 M. N2 (g) + O2 (g) --> 2NO (g) If more NO is added, bringing its concentration to 0.700 M, what will the final concentration of NO be after equilibrium is re-established?

**math**

In 1980, the population of a certain country was about 161 000. since then the population has decreased about 1% per year. a. find an equation to model the population since 1980 b. estimate the population in 1990 c. suppose the current trend continues. predict the population ...

**problem of the week**

Imagine one large cube made of 1000 white centimeter cubes. Suppose the outside of the large cube was painted black. How many of the small white cubes would have the following? 1) 0 faces painted black 2) 1 face painted black 3) 2 faces painted black 4) 3 faces painted black

**CHEM 136**

A sample of 25.00 mL of 0.100 M HNO2(in a flask) is titrated with 0.150 M of NaOH solution at 25 degrees. 1) calculate the volume(Ve) of the NaOH solution needed to completely neutralize the acid in the flask. 2)calculate the pH for (a)the initial acid solution in the flask (b...

**Math**

D.600