hershi

Suppose population proportion1 = 0.4, sample size1 = 100, population proportion2 = 0.5, sample size2 = 120. whats the formula? i think this is just a plug and chug

11 years ago

The mass of an individual atom of calcium is 40.08 amu. How many atoms would weigh a total of 15.46 g of this element if the mass of 1 amu is 1.6605x10-24 g?

11 years ago

What is the total molar concentration of ions in 45.26 mL of 0.2068 M K2CO3 (a strong electrolyte)?

11 years ago

What is the the energy (in Joules per photon) of visible radiation that has a wavelength of 6.405e-7 meters? The speed of light is 3.00x108 m/s and Planck's constant is 6.626x10-34 J*s.

11 years ago

The normal boiling point of Rh is 3727°C. What is its vapor pressure in mm Hg at 2914°C, if its heat of vaporization is 557.0 kJ/mol?

11 years ago

a solution is prepared by mixing 2.17g of an unknown non-electrolyte with 225.0g of chloroform. The freezing point of the resulting solution is -64.2 C . The freezing point of pure chloroform is -63.5 C and its kf= 4.68C m^-1 . What is the molecular mass...

11 years ago

A solution is made by dissolving 7.084 g of aluminum nitrate, Al(NO3)3, in 123.0 g of water. What is the mass percentage of solute in this solution? this feels like a simple problem but i just don't know. divide the two?

11 years ago

The solubility of Ar in water at 321.9 torr is 0.02538 g/L. What is Henry's Law constant (M/atm) for Ar in water?

11 years ago

Rubidium metal, Rb, crystallizes in a body-centered cubic arrangement. What is the radius of one atom of Rb, if its density is 1.5320 g/cm3?

11 years ago

Determine the rate of consumption of I− if the initial concentration of IO3− was 0.6634 M and decreased to 0.5745 M after 0.3964 hours. Use the reaction below. IO3− + 5I− + 6H+ ↔ 3I2 + 3H2O

11 years ago

A certain metal crystallizes in a face-centered cubic arrangement and has a density of a density and atomic radius of 12.41 g/cm3 and 134.5 pm, respectively. Which element below is it?

11 years ago

What would the [H3O+] be after addition of 5.15 mL of 0.1000 M HCl to 25.00 mL of 0.1000 B (a weak base, Kb = 6.31e-5)?

11 years ago

Which base listed below would be the best to creat a buffer having a pH of 5.0230? hydrazine, Kb = 8.90e-7 methylamine, Kb = 3.70e-4 ethanolamine, Kb = 3.20e-5 pyridine, Kb = 1.40e-9

11 years ago

What would the [OH-] be after addition of 17.47 mL of 0.1000 M NaOH to 25.00 mL of 0.1000 HA (a weak acid, Ka = 3.16e-4)?

11 years ago

Determine the molar solubility of AgBr (Ksp = 5.40e-13) in 2.502 M NH3 if the complex ion [Ag(NH3)2]+ forms with a Kf = 1.70e7 will I need to make an chemical equation using the compounds they give me? and then do an ICE table?

11 years ago

From the reaction below, calculate the free energy of formation for C3H6(g) at 25°C, if ΔGfo(CH4(g)) is -50.790 kJ/mol. 3CH4(g) ↔ C3H6(g) + 3H2(g) ΔGo = 215.302 kJ/mol i've tried doing final-initial, and products minus reactants but i'm not getting the ri...

11 years ago

What is the free energy change at 25°C for the reaction below, if ΔGfo(CH4(g) = -50.790 kJ/mol, ΔGfo(C7H14(g)) is 95.887 kJ/mol. C7H14(g) + 7H2(g) ↔ 7CH4(g) similar question but gives some different G's

11 years ago

In tomatoes, tall(D) is dominant over dwarf (d) and smooth fruit(P) is dominant over pubescent fruit (p), which is covered with fine hairs. A farmer has two tall and smooth tomato plants, which we will call plant A and plant B. The farmer crosses plants A...

11 years ago

A man marries a woman who is heterozygous for a recessive X-linked lethal gene "X" expressed in very early development. If the couple had many normal children, what would be the predicted sex ratio among their children? I'm so confused. If it's a lethal a...

10 years ago

I don't understand that equation. Which part of what's given would fit into it? T1=3727 T2=2914 then convert to kelvin. delta h is 557.0. but what do i use for R..or is that what i am looking for?

11 years ago

oh R is constant.

11 years ago

thank you

11 years ago

3(2.02) + 3(12.01) + 6.06 = 48.15 mol products 3(12.01)+ 3(4.04)=48.15 mol reactants Prod-React=0

11 years ago