What is the volume of one mole of any gass at STP?

What holds the two strands of a DNA molecule together?A. Ionic bonds between negatively and positively charged ionsB. Covalent b

statuscvo [17]

Answer:

D. Hydrogen bonds between complementary base pairs89

Explanation:

A DNA molecule is composed of two long polynucleotide chains made of four types of nucleotide subunits, two purines (adenine and guanine) and two pyrimidines (cytosine and thymine). These nucleotides are joined by covalent bonds forming a phosphate-sugar backbone. These strands are held to one another with hydrogen bonds between the base portions of complementary nucleotides.

I hope you find this information useful and interesting! Good luck!

8 0

3 years ago

2.50 L of a gas at standard temperature and pressure is compressed to 575 mL. What is the new pressure of the gas

BartSMP [9]

Answer:

reek

Explanation:

hi

5 0

3 years ago

Using the equations 2 Sr(s) + O₂ (g) → 2 SrO (s) ∆H° = -1184 kJ/mol SrO (s) + CO₂ (g) → SrCO₃ (s) ∆H° = -234 kJ/mol CO₂ (g) → C(

kkurt [141]

Answer: The $\Delta H^o_{rxn}$ for the reaction is 72 kJ.

Explanation:

Hess’s law of constant heat summation states that the amount of heat absorbed or evolved in a given chemical equation remains the same whether the process occurs in one step or several steps.

According to this law, the chemical equation is treated as ordinary algebraic expressions and can be added or subtracted to yield the required equation. This means that the enthalpy change of the overall reaction is equal to the sum of the enthalpy changes of the intermediate reactions.

The given chemical reaction follows:

$2SrCO_3(s)\rightarrow 2Sr(s)+2C(s)+3O_2(g)$ $\Delta H^o_{rxn}=?$

The intermediate balanced chemical reaction are:

(1) $2Sr(s)+O_2(g)\rightarrow 2SrO(s)$ $\Delta H_1=-1184kJ$

(2) $SrO(s)+CO_2(g)\rightarrow SrCO_3(s)$ $\Delta H_2=-234kJ$ ( × 2)

(3) $CO_2(g)\rightarrow C(s)+O_2(g)$ $\Delta H_3=394kJ$ ( × 2)

The expression for enthalpy of the reaction follows:

$\Delta H^o_{rxn}=[1\times (\Delta H_1)]+[2\times (-\Delta H_2)]+[2\times (\Delta H_3)]$

Putting values in above equation, we get:

$\Delta H^o_{rxn}=[(1\times (-1184))+(2\times -(-234))+(2\times (394))]=72kJ$

Hence, the $\Delta H^o_{rxn}$ for the reaction is 72 kJ.

4 0

3 years ago

Which plate, oceanic or continental, must be more dense?

musickatia [10]

Answer:

Oceanic & Continental Plates

The oceanic plate is denser and sinks due to its lower buoyancy. It's sucked into the asthenosphere and is melted deeper into the Earth, called a subduction zone. The continental plate is less dense and floats over the top of it since it is more buoyant

4 0

3 years ago

How do you calculate mass using density and volume?

skad [1K]

Example:

Mass = ?

Density = 25 g/mL

Volume = 5 mL

therefore:

d = m / V

25 = m / 5

m = 25 x 5

m = 125 g

hope this helps!

7 0

3 years ago