X ml - <span>25% alcohol mixture
y ml - </span><span>90% alcohol mixture
x+y = 455
0.25x ml alcohol in </span>x ml of 25% alcohol mixture
0.9y ml alcohol in y ml of 90% alcohol mixture
0.75*455= 341.25 ml alcohol in 455 ml of 75% alcohol mixture
0.25x+0.9y=341.25
System of equations:
x+y = 455 /*(-0.25) ------> -0.25x-0.25y = -0.25*455
0.25x+0.9y=341.25
-0.25x-0.25y=-113.75
0.25x+0.9y=341.25 Add both equations
0.25x+0.9y-0.25x-0.25y=341.25-113.75
0.65y =227.5
y=227.5/0.65 = 350 ml of 90% alcohol mixture
x+y=455
x+355=455
x=100 ml of 25% alcohol mixture
Answer:
You need the Delta H fusion for water. Multiply that by 50 grams. Then multiply 50 g x 4.184 x 65 to get joules to raise water to 65 degrees. Add these values together to get total joules.
Explanation:
Answer:
Covalent bonds are formed when electrons are shared between elements that are nonmetals. The ammonium ion, NH+4 , would have covalent bonds because both nitrogen and hydrogen are nonmetals. ... The rest of the bonds all contain electrons from both hydrogen and nitrogen, so they would be considered ordinary covalent bonds.
Answer:
B There are two grams of hydrogen for each gram of carbon in this compound.
Explanation:
The second option is a wrong interpretation of this chemical representation of formaldehyde.
Formaldehyde is an organic compound with the formula CH₂O.
As this is the simplest formula of the compound, it is the empirical formula. Also, the formula is the actual one for the compound and it is the molecular formula.
Chemically, the formula shows 1 mole of carbon, 2 moles of H and 1 mole of oxygen in the compound.
- A mole of a substance is more a less a unit of measurement in chemistry and it is the amount of substance that contains the avogadro's number of particles.
This ratio is not the mass of chemical species in the compound. You cannot tell the mass of elements in a compound by merely looking at the formula.
