Can you guys help me with these chem questions there’s 12....??

The value of a scientific variable:

beks73 [17]

Answer:

A

Explanation:

4 0

3 years ago

Which one is idk what it is giving brainliest

Salsk061 [2.6K]

Answer:

B or C

Explanation:

I don't really know sorry.

8 0

3 years ago

Read 2 more answers

A 10.0-milliliter sample of NaOH(aq) is neutralized by 40.0 milliliters of 0.50 M HCl. What is the molarity of the NaOH(aq)?

Ludmilka [50]

$\frac{10 mL}{1000 mL} = 0.01 L$

$\frac{40mL}{1000mL} =0.04L$

$M _{1} V_{1}=M_{2}V_{2}$

$M_{1}(0.01)=(0.50)(0.04)$

$M_{1}(0.01)=0.02$

$M_{1}= \frac{0.02}{0.01}$

$M_{1}=2$

3 0

4 years ago

95. Using the standard enthalpy of formation data in Appendix G, calculate the bond energy of the carbon-sulfur double bond in C

prohojiy [21]

Answer:

+523 kJ.

Explanation:

The following data will be used to calculate the average C-S bond energy in CS2(l).

S(s) ---> S(g)

ΔH = 223 kJ/mol

C(s) ---> C(g)

ΔH = 715 kJ/mol

Enthalpy of formation of CS2(l)

ΔH = 88 kJ/mol

CS2(l) ---> CS2(g)

ΔH = 27 kJ/mol

CS2(g) --> C(g) + 2S(g)

So we must construct it stepwise.

1: C(s) ---> C(g) ΔH = 715 kJ

2: 2S(s) ---> 2S(g) ΔH = 446 kJ

adding 1 + 2 = 3

ΔH = 715 + 446

= 1161 kJ

3: C(s) + 2S(s) --> C(g) + 2S(g) ΔH = 1161 kJ

4: C(s) + 2S(s) --> CS2(l) ΔH = 88 kJ

adding (reversed 3) from 4 = 5

ΔH = -1161 + 88

= -1073 kJ

5: C(g) + 2S(g) --> CS2(l) ΔH = -1073 kJ

6: CS2(l) ---> CS2(g) ΔH = 27 kJ

adding 5 + 6 = 7

ΔH = -1073 + 27

= -1046 kJ

7. C(g) + 2S(g) --> CS2(g) ΔH = -1046 kJ

Reverse and divide by 2 for C-S bond enthalpy

= -(-1046)/2

= +523 kJ.

8 0

3 years ago

Name the element described in each of the following:

borishaifa [10]

Alkaline earth metal whose cation isoelectric with Kr is strontium (Sr).

What is Alkaline earth metal?

Six chemical elements from group 2 of the periodic chart make up the alkaline earth metals. They are boron (R), barium (Ba), calcium (Ca), strontium (Sr), magnesium (Mg), beryllium (Be), and radium (Ra). The elements share many characteristics, including being glossy, silvery-white, moderately reactive metals at standard pressure and temperature.

They share a full outer s-orbital structurally, meaning that this orbital includes all two of its electrons, which the alkaline earth metals rapidly lose to form cations with a charge of +2 and an oxidation state of +2.

All of the identified alkaline earth metals are found in nature, albeit radium is not a primordial element but only appears as part of the decay chain of uranium and thorium.

The chemical element strontium has the atomic number 38 and the symbol Sr. Strontium is a soft, silver-white, yellowish metallic element that is an alkaline earth metal and has a strong reactivity to chemicals. When the metal is exposed to air, a thick layer of dark oxide forms. Similar to its two vertical neighbors in the periodic table, barium and calcium, strontium exhibits physical and chemical characteristics. It is mostly obtained from the minerals celestine and strontianite, where it is found naturally.

To learn more about Strontium click on the link below:

brainly.com/question/19904990

#SPJ4

8 0

2 years ago