Culinary arts HELP FAST 1. Most people don't often think about science and restaurants or the food industry as

What positions in the ring of a purine nucleotide in DNA have the potential to form hydrogen bonds but are not involed in watson

m_a_m_a [10]

Answer:

N-1

Explanation:

All nitrogen positions in purine rings (N-1, N-3, N-7 and N-9) have the potential to form hydrogen bonds. Among them, only N-1 is involved in Watson-Crick base pairing hydrogen bond with a pyridimine. N-3 and N-7 are available to form further hydrogen bonds and N-9 is involved in a N-glycosyl linkage with a desoxyribose.

6 0

3 years ago

Suppose 20.23 g of glucose are dissolved in 95.75 g of water at 27.0 OC. Glucose is nonvolatile (has no vapor pressure) and has

leonid [27]

Answer:

Explanation:

From the information given :

we can understand the solute is glucose and the solvent is water,

So, the weight of glucose = 20.23 g

the molecular weight of glucose = 180.2 g/mol

weight of water = 95. 75 g

the molecular weight of water = 18.02 g/mol

pure vapor pressure of water $P_A = 26.7 \ mmHg$ at 27°C

moles of glucose = weight of glucose/ molecular weight of glucose

= 20.23/180.2

= 0.11 mole

moles of water = weight of water / molecular weight of water

= 95.75/18.02

= 5.31 mole

mole fraction of glucose $X_{glucose} =$ (moles of glucose)/(moles of glucose+ moles of water)

$X_{glucose} =$ 0.11/(0.11 + 5.31)

$X_{glucose} =$ 0.0203

mole fraction of glucose $X_{water} =$ (moles of water)/(moles of water+ moles of glucose)

$X_{water} =$ 5.31/ (5.31 + 0.11)

$X_{water} =$ 0.9797

Using Raoult's Law:

$P_S = P^0_A \times X_A \ \ \ OR \ \ \ P_A = P^0_A \times X_A$

where:

$P_S$ = vapor pressure of the solution

$P_A$ = total vapor pressure of the solution

$P^0_A$ = vapor pressure of the solvent in the pure state

$X_A$ = mole fraction of solvent i.e. water

$P_A =$ 95.75 × 0.9797

$P_A =$ 93.81 mmHg

the total vapor pressure of the solution = 93.81 mmHg

4 0

3 years ago

A calorimeter contains 35.0 mLmL of water at 15.0 ∘C∘C . When 2.20 gg of XX (a substance with a molar mass of 56.0 g/molg/mol )

Temka [501]

Answer:

ΔH rx = -43.5 kJ / mol

Explanation:

In water, Xdissolves thus:

X(s) + H₂O(l) → X(aq) + H₂O(aq)

It is possible to find the heat in dissolution process using coffee cup calorimeter equation:

Q = -m×C×ΔT

Where Q is heat, m is mass of solution (35.0g -density 1g/mL- + 2.20g = 37.2g), C is specific heat of solution (4.18J/g°C), and ΔT is change in temperature (26.0°C-15.0°C = 11.0°C)

Replacing:

Q = -37.2g×4.18J/g°C×11.0°C

Q = -1710J = -1.71kJ

As enthalpy is the change in heat per mole of reaction, moles of X that reacted were:

2.20g X × (1mol / 56.0g) = 0.0393 moles

As heat produced per 0.0393moles was -1.71kJ, heat per mole of X is:

-1.71kJ / 0.0393mol = -43.5 kJ / mol = ΔH rx

6 0

3 years ago

A car with constant speed travelso 150 km in 7200 seconds what is the speed of the car

liberstina [14]

7200sec÷60sec in a minute÷60minutes in an hour=2hours. 150km÷ 2 hours= 75 km/hour

4 0

3 years ago

Atoms that have the same number of outer electrons

BARSIC [14]

I can see two answers, I’d go with D, but all neutral atoms, of the same element would have the same number of outer electrons. However, if you consider that some of the atoms might be ions, that would eliminate B.

4 0

3 years ago