A positive test with 2,4 dinitrophenylhydrazine could indicate the presence of which of the following functional groups ?

Ii. What is the purpose of the scientific method? (2 points)

Katena32 [7]

Explanation:

What is the purpose of the scientific method?

ans/

the goal of any scientific method is to solve a problem or to better understand an observed event.

b.

i. What does the law of conservation of energy say?

ans/

The law of conservation of energy states that energy can neither be created nor destroyed - only converted from one form of energy to another.

ii. List two different kinds of energy.

ans/

Potential energy.

Kinetic energy.

iii. What does the law say about changes energy can undergo?

ans/

The implication of the Law of Conservation of Energy is that for any energy conversion, if a certain type, or form, of energy gets reduced by a certain amount, then another type of energy must increase by the same amount.

6 0

3 years ago

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Given the following, determine ΔG°f at 298 K for SnO. Sn(s) + SnO2(s) → 2SnO(s) ; ΔG° = 12.0 kJ at 298K

Virty [35]

Answer:

The value of change in Gibbs free energy for tin(II) oxide solid is -251.9 kJ/mol.

Explanation:

$Sn(s) + SnO_2(s)\rightarrow 2SnO(s), \Delta G_{f}^{o} = 12.0 kJ$

$\Delta G_{f,SnO_2}^{o}= -515.8kJ/mol$

$\Delta G_{f,Sn}^{o}= 0 kJ/mol$

$\Delta G_{f,SnO}^{o}=?$

$\Delta G_{f}^{o}=\sum ((\Delta G_{f}^{o})_ {products})-\sum ((\Delta G_{f}^{o})_ {reactants})$

$12.0 kJ=(2 mol\times \Delta G_{f,SnO}^{o})-(1mol\times 0 kJ/mol+1 mol\times -515.8 kJ/mol)$

$\Delta G_{f,SnO}^{o}=-251.9 kJ/mol$

The value of change in Gibbs free energy for tin(II) oxide solid is -251.9 kJ/mol.

3 0

3 years ago

A 0.08541 g sample of gas occupies 10.0-ml at 288.5 k and 1.10 atm. upon further analysis, the compound is found to be 13.068% c

topjm [15]

C2Br2 First, we need to determine how many moles of the gas we have. For that, we'll use the Ideal Gas Law which is PV = nRT where P = pressure (1.10 atm = 111458 Pa) V = volume (10.0 ml = 0.0000100 m^3) n = number of moles R = Ideal gas constant (8.3144598 (m^3 Pa)/(K mol) ) T = Absolute temperature Solving for n, we get PV/(RT) = n Now substituting our known values into the formula. (111458 Pa * 0.0000100 m^3) / (288.5 K * 8.3144598 (m^3 Pa)/(K mol)) = (1.11458/2398.721652) mol = 0.000464656 mol Now let's calculate the empirical formula for this compound. Atomic weight carbon = 12.0107 Atomic weight bromine = 79.904 Relative moles carbon = 13.068 / 12.0107 = 1.08802984 Relative moles bromine = 86.932 / 79.904 = 1.087955547 So the relative number of atoms of the two elements is 1.08802984 : 1.087955547 After dividing all numbers by the smallest, the ratio becomes 1.000068287 : 1 Which is close enough to 1:1 for me to consider the empirical formula to be CBr Now calculate the molar mass of CBr 12.0107 + 79.904 = 91.9147 Finally, let's determine if the compound is actually CBr, or something like C2Br2, or some other multiple. Using the molar mass of CBr, multiply by the number of moles and see if the result matches the mass of the gas. So 91.9147 g/mol * 0.000464656 mol = 0.042708701 g 0.0427087 g is a lot smaller than 0.08541 g. So the compound isn't exactly CBr. Let's divide them to see what the factor is. 0.08541 / 0.0427087 = 1.99982673 1.99982673 is close enough to 2 to within the number of significant digits we have for me to claim that the formula for the unknown gas isn't CBr, but instead is C2Br2.

3 0

3 years ago

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How many moles contain 5.34 x 10^26 atoms of iron?

SCORPION-xisa [38]

Answer: 1.31 × 10^47 sorry if its not the answer

Explanation:

6 0

3 years ago

The pH of an unknown strong acid is 2. What is the hydronium ion concentration?

MissTica

Answer: Finding the [H3O+] and pH of Strong and Weak Acid Solutions The larger the Ka, the stronger the acid and the higher the H+ concentration at equilibrium. hydronium ion, H3O+, 1.0, 0.00, H2O, 1.0×10−14, 14.00.

Explanation:The hydrogen ion in aqueous solution is no more than a proton, a bare ... the interaction between H+ and H2O .

8 0

3 years ago