Modelová Otázka ID 2741 - 
Jaký je hmotnostní zlomek dusíku v dusitanu sodném? Ar(N) = 14; Ar(Na) = 23
Správná odpověď je: A
1 mol NaNO2 obsahuje 1 mol sodíku, 1 mol dusíku a 2 moly kyslíku. Hmotnost dusíku v 1 molu NaNO2 je 14 g, hmotnost 1 molu NaNO2 vypočítáme jako 23 + 14 + (2 · 16) = 69 g. Vzorec pro výpočet hmotnostního zlomku bude vypadat následovně:
W = m(N)/m(NaNO2) = 14/69 = 0,20.
| Cookie | Délka | Popis |
|---|---|---|
| _fbp | 3 months | Facebook sets this cookie to display advertisements when either on Facebook or on a digital platform powered by Facebook advertising after visiting the website. |
| _ga | 1 year 1 month 4 days | Google Analytics sets this cookie to calculate visitor, session and campaign data and track site usage for the site's analytics report. The cookie stores information anonymously and assigns a randomly generated number to recognise unique visitors. |
| _ga_* | 1 year 1 month 4 days | Google Analytics sets this cookie to store and count page views. |
| sbjs_current | session | Sourcebuster sets this cookie to identify the source of a visit and stores user action information in cookies. This analytical and behavioural cookie is used to enhance the visitor experience on the website. |
| sbjs_current_add | session | Sourcebuster sets this cookie to identify the source of a visit and stores user action information in cookies. This analytical and behavioural cookie is used to enhance the visitor experience on the website. |
| sbjs_first | session | Sourcebuster sets this cookie to identify the source of a visit and stores user action information in cookies. This analytical and behavioural cookie is used to enhance the visitor experience on the website. |
| sbjs_first_add | session | Sourcebuster sets this cookie to identify the source of a visit and stores user action information in cookies. This analytical and behavioural cookie is used to enhance the visitor experience on the website. |
| sbjs_migrations | session | Sourcebuster sets this cookie to identify the source of a visit and stores user action information in cookies. This analytical and behavioural cookie is used to enhance the visitor experience on the website. |
| sbjs_session | 1 hour | Sourcebuster sets this cookie to identify the source of a visit and stores user action information in cookies. This analytical and behavioural cookie is used to enhance the visitor experience on the website. |
| sbjs_udata | session | Sourcebuster sets this cookie to identify the source of a visit and stores user action information in cookies. This analytical and behavioural cookie is used to enhance the visitor experience on the website. |
| Cookie | Délka | Popis |
|---|---|---|
| lp_session_guest | 2 days | Description is currently not available. |
| uloha_switch | 1 day | Description is currently not available. |
