All categories

3 years ago

This chart lists four elements from the periodic table.

Chemistry

2 answers:

aksik [14]3 years ago

3 0

Iodine and Calcium is the correct answer

PilotLPTM [1.2K]3 years ago

3 0

Answer: d. iodine and calcium

Explanation: Ionic bonds are formed by transfer of electrons between metal and non metals.

Covalent bonds are formed by sharing of electrons between non metals

Electronic configuration of calcium:

$[Ca]=[Ar]4s^2$

Calcium atom will lose two electron to gain noble gas configuration and form calcium cation with +2 charge.

$[Ca^{2+}]={Ar]$

Electronic configuration of iodine:

$[I]=[Kr]4d^{10}5s^25p^5$

Iodine atom will gain one electron to gain noble gas configuration and form iodide ion with -1 charge.

$[I^-]=[Kr]4d^{10}5s^25p^6$

In calcium iodide the one electron from calcium metal gets transferred to iodine atom and thus form an ionic bond to give $CaI_2$

You might be interested in

An unbalanced equation is shown. In this reaction, 200.0 g of FeS2 is burned in 100.0 g of oxygen, and 55.00 g of Fe2O3 is produ

Crazy boy [7]

<span>4FeS2 + 11O2 = 2Fe2O3 + 8SO2</span>

Percent yield is calculated as the actual yield divided by the theoretical yield multiplied by 100.

Actual yield = 55 g ( 1 mol / 159.69 g ) = 0.34 mol Fe2O3

To find for the theoretical yield, we first determine the limiting reactant.

100 g O2 ( 1 mol / 32 g) = 3.13 mol O2
200 g FeS2 (1 mol / 119.98g) = 1.67 mol FeS2

Therefore, the limiting reactant is O2.

Theoretical yield = 3.13 mol O2 ( 2 mol Fe2O3 / 11 mol O2 ) = 0.57 mol Fe2O3

Percent yield = (0.34 mol / 0.57 mol) x 100 = 59.74%

3 0

2 years ago

If 8.500 g CH is burned and the heat produced from the burning is added to 5691 g of water at 21 °C, what is the final

mojhsa [17]

The final temperature = 36 °C

<h3>Further explanation</h3>

The balanced combustion reaction for C₆H₆

2C₆H₆(l)+15O₂(g)⇒ 12CO₂(g)+6H₂O(l) +6542 kJ

MW C₆H₆ : 78.11 g/mol

mol C₆H₆ :

$\tt \dfrac{8.5}{78.11}=0.109$

Heat released for 2 mol C₆H₆ =6542 kJ, so for 1 mol

$\tt \dfrac{0.109}{2}\times 6542=356.539~kJ/mol$

Heat transferred to water :

Q=m.c.ΔT

$\tt 356.539=5.691~kg\times 4.18~kj/kg^oC\times (t_2-21)\\\\t_2-21=15\rightarrow t_2=36^oC$

3 0

2 years ago

What is the ph of a solution that is 0.50 m in propanoic acid and 0.40 m in sodium propanoate. (ka for propanoic acid = 1.3 x 10

max2010maxim [7]

<span>The pH is given by the Henderson - Hasselbalch equation:
              pH = pKa + log([A-]/[HA])
              pH = -log(</span><span>1.3 x 10^-5) + log(0.50/0.40)
              pH = 4.98
The answer to this question is 4.98.
</span>

3 0

3 years ago

what is the percent yield of NaCl if 31.0 g of CuCl reacts with excess NaNo3 to produce 21.2 g of NaCl

olchik [2.2K]

Percentage Yield = (Actual Yield ÷ Theoretical Yield) × 100

The Actual Yield is given in the question as 21.2 g of NaCl. However, in order to find the theoretical yield, you have to write a balanced equation and use the mole ratio to calculate the mass of NaCl that would be produced.

Balanced Equation: CuCl + NaNO₃   → NaCl + CuNO₃

Moles of CuCl = Mass of CuCl ÷ Molar Mass of CuCl
= 31.0 g ÷ (63.5 + 35.5)g/mol
= 0.31 mol

the mole ratio of CuCl to NaCl is 1 : 1,
∴ if moles of CuCl = 0.31 mol,

then moles of NaCl = 0.31 mol

Now, Mass of NaCl = Moles of NaCl × Molar Mass of NaCl
= 0.31 mol × (23 + 35.5) g/mol
= 18.32 g

⇒ the THEORETICAL Yield of NaCl, in this case, is 18.32 g.

Now, since Percentage Yield = (Actual Yield ÷ Theoretical Yield) × 100

⇒ Percentage Yield of NaCl = (21.2g ÷ 18.32g) × 100
= 115.7 %

NOTE: Typically, the percentage yield of a reaction is less than 100%, however in a case where the mass of the substance is weighed with impurities, then that mass may be in excess of 100% as seen here.

4 0

3 years ago

Damage to which of the following would disrupt the process of photosynthesis?

Marta_Voda [28]

A, the chloroplast is where photosynthesis occurs

8 0

2 years ago