Question

A. Calculations for the Determination of Ammonium Chloride The data from the data entry portion of the report has been copied into this section of the report for your convenience. Use the data to make the necessary calculations.
(1) Mass of evaporating dish on #1: 38.646
(2) Mass of evaporating dish and original sample (a): 39 591
(3) Mass of evaporating dish after subliming Nha (g) 39.4750
B. Calculations for the Determination of Sodium Chloride 14 Mass of evaporating dish #2: IS Mass of watch glass (a):
(1) Mass of evaporating dish #2 38700 g
(2) Mass of watch glass. 28 299 g
(3) Mass of evaporating dish #2, watch glass and NaCl(a): 67,355
C. Calculations for the Determination of Sand
Mass of evaporating dish #1: 38.645
Mass of evaporating dish and SiO2 (g) 39.405
D. Summary
Mass of original sample (0)
Experimental mass recovered (NH4Cl + NaCl + S107)
Differences in these weights (g) (use the absolute value of the difference)
recovery of matter
Select a reasonable explanation to account for the differences. There may be more than one possible reason that makes sense, just select one of them.
A. It is possible not all of the water was evaporated from the sand, causing the recovered mass to be higher.
B. It is possible not all of the water was evaporated from the sand, causing the recovered mass to be lower.
C. While drying the NaCl, the liquid bolled and some splattered out of the evaporating dish, causing the recovered mass to be lower.
D. While drying the Naci, the liquid boiled and some splattered out of the evaporating dish, causing the recovered mass to be higher.
E. There was no difference in recovered and original mass, so there is no difference to account for.

Answer 1

Answer:

A

Explanation:

Considering question A

Mass of  original sample is $m_o = 0.945 \ g$

Mass of   NH4Cl is  $m_n = 0.116 \ g$

Percent of  NH4Cl is $k = 12.275 \%$

B

Mass of  NaCl  $m_k = 0.359 \ g$

C

Mass  of  SiO2   $m_e = 0.46$

D

 Mass of original sample $m_o = 0.945 \ g$

  Differences in these weights (g) (use the absolute value of the difference)

recovery of matter   $G = 0.01 \ g$

The  correct option is C

From the question we are told that

The mass of evaporating dish on #1 is  $m_1 = 38.646 \ g$

 The mass of evaporating dish and original sample   $m_2 = 39 591 \ g$

  The mass of evaporating dish after subliming $NH_4Cl$ is $m_3 = 39.4750 \ g$

Generally the mass of the original sample is  mathematically represented as

        $m_o = m_2 - m_1$

=>     $m_o = 39 591 - 38.646$

=>     $m_o = 0.945 \ g$

Generally the mass of $NH_4Cl$ is mathematically represented as

        $m_n = m_2 - m_3$

=>      $m_n = 39 591 - 39.4750$

=>      $m_n = 0.116 \ g$

The  Percent  $NaH_4 Cl (g)$

        $k = \frac{ m_n}{m_o} *100$

=>     $k = \frac{0.116 }{0.945} *100$

=>      $k = 12.275 \%$

Considering question B

The  mass of evaporating dish #2 is  $m_g = 38700\ g$

The  mass of  watch glass is   $m_a = 28 299 \ g$

The mass of evaporating dish #2, watch glass and NaCl  $m_b = 67,355 \ g$

Generally the mass of NaCl is  

       $m_k = m_b -[m_g + m_a]$

=>     $m_k = 67,355 -[38700 + 28 299]$

=>      $m_k = 0.359 \ g$

Considering question C

 The mass of evaporating dish is   $m_p= 38.645$

 The mass of evaporating dish and SiO2     $m_s = 39.105 \ g$

Generally  the mass of  SiO2  is  mathematically represented as

        $m_e = 39.105 - 38.645$

=>      $m_e = 0.46$

Considering  D

The  mass of the original  sample  is  $m_o = 0.945 \ g$

Generally the experimental  mass recovered (NH_4Cl,NaCl, SiO2 ) is mathematically evaluated as

     $M =0.116 + 0.46 + 0.359$

    $M = 0.935 \ g$

Generally the differences in these weights (g) of recovery of matter is mathematically represented as.

     $G =0.945- 0.935$

=>   $G = 0.01 \ g$

While drying the NaCl, the liquid boiled and some splattered out of the evaporating dish, causing the recovered mass to be lower.