CREATE TABLE table_2780146_6 (hc__g_kwh_ VARCHAR, no_x__g_kwh_ VARCHAR)

What's the HC for the standard with NO x of 7.0 g/kWh?
SELECT hc__g_kwh_ FROM table_2780146_6 WHERE no_x__g_kwh_ = "7.0"
SELECT "hc__g_kwh_" FROM "table_2780146_6" WHERE "7.0" = "no_x__g_kwh_"