Template:Chem molar mass

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This template calculates the molecular mass (or molar mass) of a chemical compound. It is designed to be embedded in infoboxes {{Infobox drug}} and {{Chembox}}, but it can be used in-line just as well.

Parameters

Use chemical symbols to compose the molecular formula: {{Chem molar mass|H=2|O=1}} (for H₂O) → 18.02 g·mol⁻¹

|round= by default the calculated number is rounded to 2 decimals.

|round=no will show all decimals:

{{Chem molar mass|Be=1|round=no}} → 9.0121831 g·mol⁻¹

|round=a number will round to that number of decimals

{{Chem molar mass|Be=1|round=4}} → 9.0122 g·mol⁻¹

|unit= changes the unit for the calculated result. The default unit is g·mol⁻¹.

{{Chem molar mass|H=2|O=1|unit=gram per mole}} → 18.02 gram per mole

The next parameters will always show:
|fixed= to enter a fixed (predefined) value+unit. It will overwrite any calculated value+unit.

|ref=<ref>some source</ref> will add the reference right after the unit.

|comment=Any textis added as a suffix, after a space and unedited (no brackets added etc.).

Example:

{{Chem molar mass|fixed=234.56 g·mol<sup>−1</sup>|ref=<ref>Some source</ref>|comment=My Comment}} → 234.56 g·mol⁻¹^[1] My Comment

|sortable=yes, for use in sortable tables: will add a hidden sortable number, and omits the unit (see table below).

Blank parameter list

{{Chem molar mass
| round   =
| unit    =
| fixed   =
| ref     =
| comment =
| sortable=
| catname =
}}

{{Chem molar mass
<!-- with 118 chemical symbols: -->|H= |He= |Li= |Be= |B= |C= |N= |O= |F= |Ne= |Na= |Mg= |Al= |Si= |P= |S= |Cl= |Ar= |K= |Ca= |Sc= |Ti= |V= |Cr= |Mn= |Fe= |Co= |Ni= |Cu= |Zn= |Ga= |Ge= |As= |Se= |Br= |Kr= |Rb= |Sr= |Y= |Zr= |Nb= |Mo= |Tc= |Ru= |Rh= |Pd= |Ag= |Cd= |In= |Sn= |Sb= |Te= |I= |Xe= |Cs= |Ba= |La= |Ce= |Pr= |Nd= |Pm= |Sm= |Eu= |Gd= |Tb= |Dy= |Ho= |Er= |Tm= |Yb= |Lu= |Hf= |Ta= |W= |Re= |Os= |Ir= |Pt= |Au= |Hg= |Tl= |Pb= |Bi= |Po= |At= |Rn= |Fr= |Ra= |Ac= |Th= |Pa= |U= |Np= |Pu= |Am= |Cm= |Bk= |Cf= |Es= |Fm= |Md= |No= |Lr= |Rf= |Db= |Sg= |Bh= |Hs= |Mt= |Ds= |Rg= |Cn= |Nh= |Lv= |Mc= |Fl= |Ts= |Og=
| round   =
| unit    =
| fixed   =
| ref     =
| comment =
| sortable=
| catname =
}}

Standard atomic weights used

Atomic number Z	Element	Molar mass g·mol⁻¹	Formal standard atomic weight (A_{r, standard})^[2]	s.a.w., formal short (A_{r, abridged and conventional})^[2]	Note

	C₉H₈O₄	&10000000000000180157000180.157			calculated from formula
	C₉H₈O₄	&10000000000000180157000180.157 g·mol⁻¹			calculated from formula
	C₉H₈O₄	&10000000000000180158999180.159			aspirin
1	H	&100000000000000010080001.008	[1.00784, 1.00811]	1.008
2	He	&100000000000000040026024.002602	4.002602(2)	4.0026
3	Li	&100000000000000069400006.94	[6.938, 6.997]	6.94
4	Be	&100000000000000090121839.0121831	9.0121831(5)	9.0122
5	B	&1000000000000001081000010.81	[10.806, 10.821]	10.81
6	C	&1000000000000001201099912.011	[12.0096, 12.0116]	12.011
7	N	&1000000000000001400699914.007	[14.00643, 14.00728]	14.007
8	O	&1000000000000001599900015.999	[15.99903, 15.99977]	15.999
9	F	&1000000000000001899840318.998403163	18.998403163(6)	18.998
10	Ne	&1000000000000002017970020.1797	20.1797(6)	20.180
11	Na	&1000000000000002298976922.98976928	22.98976928(2)	22.990
12	Mg	&1000000000000002430499924.305	[24.304, 24.307]	24.305
13	Al	&1000000000000002698153826.9815385	26.9815384(3)	26.982
14	Si	&1000000000000002808500028.085	[28.084, 28.086]	28.085
15	P	&1000000000000003097376130.973761998	30.973761998(5)	30.974
16	S	&1000000000000003206000032.06	[32.059, 32.076]	32.06
17	Cl	&1000000000000003545000035.45	[35.446, 35.457]	35.45
18	Ar	&1000000000000003994800039.948	[39.792, 39.963]	39.95
19	K	&1000000000000003909830039.0983	39.0983(1)	39.098
20	Ca	&1000000000000004007800040.078	40.078(4)	40.078(4)
21	Sc	&1000000000000004495590844.955908	44.955908(5)	44.956
22	Ti	&1000000000000004786699947.867	47.867(1)	47.867
23	V	&1000000000000005094149950.9415	50.9415(1)	50.942
24	Cr	&1000000000000005199609951.9961	51.9961(6)	51.996
25	Mn	&1000000000000005493804354.938044	54.938043(2)	54.938
26	Fe	&1000000000000005584499955.845	55.845(2)	55.845(2)
27	Co	&1000000000000005893319458.933194	58.933194(3)	58.933
28	Ni	&1000000000000005869339958.6934	58.6934(4)	58.693
29	Cu	&1000000000000006354599963.546	63.546(3)	63.546(3)
30	Zn	&1000000000000006537999965.38	65.38(2)	65.38(2)
31	Ga	&1000000000000006972299969.723	69.723(1)	69.723
32	Ge	&1000000000000007262999972.63	72.630(8)	72.630(8)
33	As	&1000000000000007492159474.921595	74.921595(6)	74.922
34	Se	&1000000000000007897100078.971	78.971(8)	78.971(8)
35	Br	&1000000000000007990399979.904	[79.901, 79.907]	79.904
36	Kr	&1000000000000008379800083.798	83.798(2)	83.798(2)
37	Rb	&1000000000000008546779985.4678	85.4678(3)	85.468
38	Sr	&1000000000000008762000087.62	87.62(1)	87.62
39	Y	&1000000000000008890583988.90584	88.90584(1)	88.906
40	Zr	&1000000000000009122400091.224	91.224(2)	91.224(2)
41	Nb	&1000000000000009290636992.90637	92.90637(1)	92.906
42	Mo	&1000000000000009595000095.95	95.95(1)	95.95
43	Tc	&1000000000000009800000098
44	Ru	&10000000000000101069999101.07	101.07(2)	101.07(2)
45	Rh	&10000000000000102905500102.9055	102.90549(2)	102.91
46	Pd	&10000000000000106420000106.42	106.42(1)	106.42
47	Ag	&10000000000000107868200107.8682	107.8682(2)	107.87
48	Cd	&10000000000000112414000112.414	112.414(4)	112.41
49	In	&10000000000000114817999114.818	114.818(1)	114.82
50	Sn	&10000000000000118709999118.71	118.710(7)	118.71
51	Sb	&10000000000000121760000121.76	121.760(1)	121.76
52	Te	&10000000000000127599999127.6	127.60(3)	127.60(3)	(Does not follow atomic number)
53	I	&10000000000000126904470126.90447	126.90447(3)	126.90	(Does not follow atomic number)
54	Xe	&10000000000000131293000131.293	131.293(6)	131.29
55	Cs	&10000000000000132905451132.90545196	132.90545196(6)	132.91
56	Ba	&10000000000000137326999137.327	137.327(7)	137.33
57	La	&10000000000000138905470138.90547	138.90547(7)	138.91
58	Ce	&10000000000000140116000140.116	140.116(1)	140.12
59	Pr	&10000000000000140907659140.90766	140.90766(1)	140.91
60	Nd	&10000000000000144241999144.242	144.242(3)	144.24
61	Pm	&10000000000000145000000145
62	Sm	&10000000000000150360000150.36	150.36(2)	150.36(2)
63	Eu	&10000000000000151963999151.964	151.964(1)	151.96
64	Gd	&10000000000000157250000157.25	157.25(3)	157.25(3)
65	Tb	&10000000000000158925350158.92535	158.925354(8)	158.93
66	Dy	&10000000000000162500000162.5	162.500(1)	162.50
67	Ho	&10000000000000164930329164.93033	164.930328(7)	164.93
68	Er	&10000000000000167258999167.259	167.259(3)	167.26
69	Tm	&10000000000000168934220168.93422	168.934218(6)	168.93
70	Yb	&10000000000000173044999173.045	173.045(10)	173.05
71	Lu	&10000000000000174966800174.9668	174.9668(1)	174.97
72	Hf	&10000000000000178490000178.49	178.49(2)	178.49(2)
73	Ta	&10000000000000180947879180.94788	180.94788(2)	180.95
74	W	&10000000000000183840000183.84	183.84(1)	183.84
75	Re	&10000000000000186206999186.207	186.207(1)	186.21
76	Os	&10000000000000190229999190.23	190.23(3)	190.23(3)
77	Ir	&10000000000000192217000192.217	192.217(2)	192.22
78	Pt	&10000000000000195084000195.084	195.084(9)	195.08
79	Au	&10000000000000196966568196.966569	196.966570(4)	196.97
80	Hg	&10000000000000200592000200.592	200.592(3)	200.59
81	Tl	&10000000000000204379999204.38	[204.382, 204.385]	204.38
82	Pb	&10000000000000207199999207.2	207.2(1)	207.2
83	Bi	&10000000000000208980400208.9804	208.98040(1)	208.98
84	Po	&10000000000000209000000209
85	At	&10000000000000210000000210
86	Rn	&10000000000000222000000222
87	Fr	&10000000000000223000000223
88	Ra	&10000000000000226000000226
89	Ac	&10000000000000227000000227
90	Th	&10000000000000232037700232.0377	232.0377(4)	232.04
91	Pa	&10000000000000231035879231.03588	231.03588(1)	231.04
92	U	&10000000000000238028909238.02891	238.02891(3)	238.03
93	Np	&10000000000000237000000237
94	Pu	&10000000000000244000000244
95	Am	&10000000000000243000000243
96	Cm	&10000000000000247000000247
97	Bk	&10000000000000247000000247
98	Cf	&10000000000000251000000251
99	Es	&10000000000000252000000252
100	Fm	&10000000000000257000000257
101	Md	&10000000000000258000000258
102	No	&10000000000000259000000259
103	Lr	&10000000000000266000000266
104	Rf	&10000000000000267000000267
105	Db	&10000000000000268000000268
106	Sg	&10000000000000269000000269
107	Bh	&10000000000000270000000270
108	Hs	&10000000000000269000000269
109	Mt	&10000000000000278000000278
110	Ds	&10000000000000281000000281
111	Rg	&10000000000000281000000281
112	Cn	&10000000000000285000000285
113	Nh	&10000000000000286000000286
114	Fl	&10000000000000289000000289
115	Mc	&10000000000000289000000289
116	Lv	&10000000000000293000000293
117	Ts	&10000000000000294000000294
118	Og	&10000000000000294000000294

Data sources (CIAAW)

Primarily, the atomic weights used here are defined by CIAAW [1]:

"Standard Atomic Weights". Commission on Isotopic Abundances and Atomic Weights (CIAAW). 2015. Retrieved 2015-09-20. (68 elements)
CIAAW also published additional lists in spreadsheet format (2013). It has additional conventional values for trade usage, and some background information on the numbers and calculations. (12 elements: B, Br, C, Cl, H, Li, Mg, N, O, S, Si, Tl).

Coplen, T.B.; Brand, W.A. (2013). "Atomic weights of the elements 2013 (xls)". CIAAW. Retrieved 2015-05-26. {{cite web}}: Unknown parameter |displayauthors= ignored (|display-authors= suggested) (help)

Some unstable elements can naturally occur, and so are listed (4 elements: Bi, Th, Pa, U)
Additional values are those of the most stable isotopes, as given in List of chemical elements (34 elements). This source is not supported by the CIAAW publications.

See also: "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. February 2016. pp. 265–291. doi:10.1515/pac-2015-0305. eISSN 1365-3075. ISSN 0033-4545. Retrieved 2016-12-29.

Possolo, Antonio; van der Veen, Adriaan M. H.; Meija, Juris; Hibbert, D. Brynn (2018-01-04). "Interpreting and propagating the uncertainty of the standard atomic weights (IUPAC Technical Report)". doi:10.1515/pac-2016-0402. Retrieved 2018-09-23.

Embedding in a template

The template is designed to be embedded in a template like {{Drugbox}}. The molecular formula can be entered like ...|H=2|O=1, and these values then are passed through to this subtemplate, together with the other parameters like |round=.

For this usage one extra parameter is available:
|catname=. A category name entered here, which will be used as maintenance category for articles that have both calculated and fixed input. These are two inputs for one data value. The maintenance task is to remove the |fixed= input (unless overwriting is intentional).

Know issue: uncertainty

Atomic weights are given with a precision and uncertainty, for example: 20.1797(6) for neon (more here).

Uncertainty

This template does not maintain the uncertainty (the bracketed part). When done correctly, the uncertainty could influence the result, especially when precision (number of decimals) is larger.

Rounding

This template usually does rounding on the calculated result, to 2 decimals by default:

For neon: {{Chem molar mass|Ne=1}} → 20.18 g·mol⁻¹

Two decimals is common practice for trade and most laboratory situations. However, rounding is set to more decimals, and the compounnd has atoms with less precision, the resulting number will be inaccurate (suggesting a wrong precision). For example strontium :

{{Chem molar mass|Sr=1|round=4}} → 87.6200 g·mol⁻¹

Six elements have values ending with a final decimal being "0" (a zero), like Sn: 118.710. This value does not show for technical reasons (the calculation 'rounds them away'), but it does signify an extra precision. The six elements are Sn, Rh, Ge, Sb, Dy, Bi.

Calculate cumulative uncertainties

[2], [3]